Editing Linguistics


== Syntax ==
The study of how '''words''' (the smallest unit of grammar that has meaning and can stand alone; the word 'car') and '''morphemes''' (smaller units than words that carry meaning but cannot stand alone; the prefix 'un-') combine to form larger units of grammar, such as phrases and sentences. Syntax confirms itself with '''word order''', '''grammatical relationships''' between words and morphemes, '''constituency''' (hierarchical structure for sentences), '''agreement''' (when words change to adapt to their neighbors in a larger combined unit of grammar), crosslinguistic variation, and the '''semantics''' (the relationship between the form of a word and its meaning). 

The word ''syntax'' comes from <u>Ancient Greek</u>: ''σύνταξις''  'coordination,' which consists of ''σύν (syn)'', 'together,' and ''τάξις (táxis)'', 'ordering.' Language played a crucial role in Greek '''philosophy''', with figures like '''[[Plato]]''' and '''[[Aristotle]]''' exploring the relationship between words, meaning, and reality. Aristotle's work on logic delved into the principles of constructing valid arguments, indirectly touching upon aspects of syntax. <u>Classical Greek</u> and <u>Hellenic</u> thinkers made substantial contributions to the study of grammar; '''Dionysius Thrax''' (100s BCE), composed the ''Tékhnē Grammatikḗ'' (''Art of Grammar''), the first work of analytical linguistics focusing on <u>Ancient Greek</u>, which included discussions on parts of speech, morphology, and syntax.

In <u>English</u>, syntax is largely controlled by word order ('the girl loves the boy' versus 'the boy loves the girl') whereas in many other languages, case markers indicate these grammatical relationships; we see this trait in <u>Latin</u> where word order is far less important - 'the girl loves the boy' can be written in a variety of correct orders because the -um ending on the object (boy) stays constant (''puerum puella amat'', ''amat puella puerum, amat puerum puella,'' or ''puella amat puerum'' are all correct. <u>Editor's note:</u> ''puella'' is girl, ''puer(-um)'' is boy, and ''amat'' is love). 

=== Word Order ===
The sequence in which the '''subject''' (S), '''verb''' (V), and '''object''' (O) ''typically'' appear in sentences. ''Typically'' is an important qualifier; while the dominant word order offers a foundational understanding, many languages exhibit flexibility in their word order, especially for emphasis, thematic structure, or in questions versus statements. 

* <u>Subject-Object-Verb</u> ('''SOV'''): Languages that typically use SOV order include <u>Japanese</u>, <u>Korean</u>, <u>Turkish</u>, and <u>Latin</u>. Around 40-45% of the world's languages are believed to use SOV as their '''default word order'''.
* <u>Subject-Verb-Object</u> ('''SVO'''): Languages that typically use SVO order include <u>English</u>, <u>Mandarin Chinese</u>, <u>Spanish</u>, and <u>Russian</u>. Approximately 35-40% of languages are thought to use SVO as their primary order.
* <u>Verb-Subject-Object</u> ('''VSO''') and <u>Verb-Object-Subject</u> ('''VOS'''): These orders are less common. VSO is seen in <u>Classical Arabic</u> and <u>Welsh</u>, while VOS appears in languages like <u>Malagasy</u> and <u>Fijian</u>. Combined, VSO and VOS might account for around 10-15% of languages.
* <u>Object-Verb-Subject</u> ('''OVS''') and <u>Object-Subject-Verb</u> ('''OSV'''): These are the rarest word orders among languages. Examples include <u>Hixkaryana</u> for OVS and <u>Xavante</u> for OSV. Together, they constitute less than 1% of all languages.

The separation by language family is as follows: 

* <u>Indo-European</u> predominantly features '''SVO''' (<u>English</u>, <u>Spanish</u>) and '''SOV''' (<u>Hindi</u>, <u>Persian</u>) orders.
* <u>Sino-Tibetan</u> languages can show diversity in structure; <u>Mandarin Chinese</u> is notably '''SVO'''.
* <u>Turkic</u> generally features '''SOV''' order, as seen in <u>Turkish</u> and <u>Uzbek</u>.
* <u>Uralic</u> features a mix, but <u>Finnish</u> and <u>Hungarian</u>, for example, tend to favor '''SVO'''.
* <u>Afro-Asiatic</u> languages like <u>Arabic</u> ('''VSO'''), <u>Hebrew</u> ('''SVO'''), and <u>Amharic</u> ('''SOV)''' show diversity.
* <u>Austronesian</u> also has this variability; <u>Indonesian</u> ('''SVO''') and <u>Malagasy</u> ('''VOS''').
* <u>Dravidian</u> primarily features '''SOV''' order, as in <u>Tamil</u> and <u>Telugu</u>.

=== Grammatical Relationships ===
The standard examples of grammatical functions from traditional grammar are '''subject''', '''direct object''', and '''indirect object'''. 

* The subject is the noun/pronoun about which a statement is made ('''John''' gave an apple to Sally). 
* The direct object is the noun/pronoun being acted upon by the verb (John gave an '''apple''' to Sally). 
* The indirect object is the recipient of the direct object (John gave an apple to '''Sally''').

Many modern theories of grammar acknowledge numerous additional types of relations ('''complement''', '''specifier''', '''predicative''', et cetera). The role of grammatical relations in theories of grammar is greatest in '''dependency grammars''', which propose dozens of distinct grammatical relations. Critics argue that overemphasis on certain grammatical models, such as word order (particularly from an <u>Indo-European</u> focus), may overlook the diversity and complexity of language structures worldwide.

* <u>Complement</u>: A word or phrase that is necessary to complete the meaning of another part of the sentence. Their main role is to complete the idea expressed by the word they complement. Without the complement, the idea would feel incomplete.
** '''Verb Complement''': Provides essential information about the action or state described by the verb. For example, in "She gave her friend a gift," "her friend a gift" is a complement of the verb "gave" because it completes the action by specifying what was given and to whom.
** '''Noun Complement''': Completes the meaning of a noun. For instance, "The decision to leave early" includes "to leave early" as a complement of "decision," explaining what the decision is about.
** '''Adjective Complement''': Completes the meaning of an adjective. In "She is capable of winning," "of winning" is a complement of "capable," specifying in what way she is capable.

* <u>Specifier</u>: A word that modifies or provides more specific information about another word, often relating to quantity, definiteness, or possession. Specifiers can be articles (the, a), possessive pronouns (his, her), demonstratives (this, that), and quantifiers (some, many).
* <u>Predicative</u>: A predicative (or predicate) element relates to the subject or object by providing information about it, typically through a linking verb (such as "to be," "seem," "become"). Predicatives can be predicative adjectives or predicative nominatives (nouns or pronouns) that describe or identify the subject or object. Predicatives provide additional information or description about the subject or object, linking it to a quality, identity, or condition.
** '''Predicative Adjective''': Describes the subject or object. In "The sky is blue," "blue" is a predicative adjective providing information about "the sky."
** '''Predicative Nominative''': Identifies or renames the subject or object. For example, in "Karen is a teacher," "a teacher" is a predicative nominative that identifies Karen's occupation.

Dependency grammars emphasize the idea that linguistic units are connected to each other by direct links or dependencies, forming a network of relations that structure the sentence. In this framework, each unit depends on a '''head''' (a central word it is connected to) and can have '''dependents''' (words that depend on it). Dependency grammars identify a wide range of specific grammatical relations to describe the types of dependencies that can exist, reflecting the nuanced ways words can relate to each other within a sentence.

Some languages, often referred to as '''non-configurational''', exhibit a high degree of flexibility in word order. Grammatical relationships are often indicated through '''inflectional morphology'''. In <u>Australian Aboriginal</u> languages, <u>Latin</u>, and <u>Classical Greek</u>, the subject, object, and verb can appear in various orders without changing the fundamental meaning of the sentence.

In '''topic-prominent''' languages, such as <u>Mandarin Chinese</u>, the '''topic''' of the sentence (what the sentence is about, which can be the subject, object, or another element) comes first, and what is said about the topic follows. This structure emphasizes the '''topic-comment construction''' over the '''subject-predicate construction''' typical of subject-prominent languages like <u>English</u>.

In languages with rich morphological systems, such as '''agglutinative''' and '''fusional''' languages, grammatical roles are often marked by case endings or through agreement rather than strictly by word order. This allows for greater flexibility in sentence structure and can convey additional nuances.

'''Polysynthetic''' languages, which include many indigenous languages of the <u>Americas</u>, incorporate a high degree of information within single words through complex '''inflection'''. This can include the subject, object, verb, and additional modifiers and relational elements, making the concept of word order as applied in more '''analytic''' languages less directly relevant.

=== Inflection ===
A process of word formation where a word is modified to express different grammatical categories such as tense, case, voice, aspect, comparatives, person, number, gender, mood, animacy, agreement, and definiteness. When a verb is inflected, it is called '''conjugation'''; when other word types (nouns, adjectives, adverbs, pronouns, determiners, participles, prepositions, postpositions, numerals, articles, aspects, et cetera) it is called '''declension'''. 

An inflection expresses grammatical categories with '''affixation''' (such as prefix, suffix, infix, circumfix, and transfix), '''apophony''' (as Indo-European '''ablaut''', sound changes to the root word), or other modifications. For example, the Latin verb ''ducam'', meaning "I will lead", includes the suffix ''-am'', expressing person (first), number (singular), and tense-mood (future indicative or present subjunctive).

The inflected form of a word often contains both '''free morphemes''' (can stand by itself as a word), and '''bound morphemes''' (cannot stand alone as a word). For example, the English word ''cars'' is a noun that is inflected for number to express the plural: the morpheme ''car'' is unbound because it could stand alone as a word, while the suffix ''-s'' is bound because it cannot stand alone as a word. These two morphemes together form the inflected word ''cars''.

Words that are never subject to inflection are said to be '''invariant'''; for example, the English verb ''must'' is an invariant item: it never takes a suffix or changes form to signify a different grammatical category. Its categories can be determined only from its context. Languages that have some degree of inflection are '''synthetic languages'''. These can be highly inflected (such as <u>Latin</u>, <u>Greek</u>, <u>Biblical Hebrew</u>, and <u>Sanskrit</u>), or slightly inflected (such as <u>English</u>, <u>Dutch</u>, <u>Persian</u>). Languages that use little inflection are also said to be 'analytic.' '''Analytic''' languages that do not make use of '''derivational''' morphemes, such as <u>Standard Chinese</u>, are said to be '''isolating'''.

===== Types of Inflections =====
Inflection often involves agreement between nouns and other parts of speech, such as adjectives, pronouns, and verbs. 

'''Cases''' indicate the grammatical role of a noun or pronoun in a sentence, such as subject, object, or possession. Common cases include: <u>Nominative</u> - subject of the verb; <u>Accusative</u> - direct object of the verb; <u>Dative</u> - indirect object of the verb; <u>Genitive</u> - possessive relation; <u>Locative</u> - location; <u>Instrumental</u> - means by which an action is performed; <u>Ablative</u> - movement away from something; <u>Vocative</u> - direct address; <u>Allative</u> - movement toward something.

'''Number''' distinguishes between one (<u>singular</u>), two (<u>dual</u>), and more than two (<u>plural</u>) entities, with some languages having additional distinctions - some languages distinguish between 'a few' and 'many' (<u>paucal</u>) or may have a particular inflection for a collective quantity. 

'''Gender''' in language can be a way to classify nouns and pronouns, often impacting agreement with adjectives, verbs, and pronouns; can generally include <u>masculine</u>, <u>feminine</u>, <u>neuter</u>, and/or <u>common</u>, among others.

'''Animacy''' can also play a role similar to gender in some languages, with <u>animate</u> or <u>inanimate</u> objects having distinct inflection markers.

'''Definiteness''' distinguishes between specific and non-specific objects ('the' versus 'a/an'). 

'''Partitive''' is used in to express something being 'part of' some bigger or greater whole. 

'''Comparison''' markers indicate comparative and superlative forms.

Many languages have <u>unique declension categories</u> not widely found elsewhere, reflecting specific semantic or syntactic distinctions important in those languages. 

In <u>English</u> most nouns are inflected for number with the inflectional plural affix ''-s'' (as in "dog" → "dog-'''s'''"), and most English verbs are inflected for tense with the inflectional past tense affix ''-ed'' (as in "call" → "call-'''ed'''"). English also inflects verbs by affixation to mark the third person singular in the present tense (with ''-s''), and the present participle (with ''-ing''). English short adjectives are inflected to mark comparative and superlative forms (with ''-er'' and ''-est'' respectively). Despite the general regularization, <u>English</u> retains traces of its ancestry, with a minority of its words still using inflection by '''ablaut''' (sound change, mostly in verbs) and umlaut (a particular type of sound change, mostly in nouns), as well as long-short vowel alternation. 

* ''Write, wrote, written'' (marking by '''ablaut''' variation, and also suffixing in the participle); s''ing, sang, sung'' (ablaut); ''foot, feet'' (marking by '''umlaut''' variation); ''mouse, mice'' (umlaut); ''child, children'' (ablaut, and also suffixing in the plural)
In <u>Latin</u>, there are five types of declension. Words that belong to the <u>first declension</u> usually end in ''-a'' and are usually feminine in gender, and thus can be said to share a common '''inflectional framework'''. In <u>Old English</u>, nouns are divided into two major categories of declension, ''strong'' and ''weak'''.''''' Through the process of '''syncretism''', the same inflection form may serve multiple grammatical functions in many languages, and context helps reveal the semantic details.

Morphemes can be added to inflectional languages in a variety of ways: 

* '''Affixation''', or simply adding morphemes onto the word without changing the root;
* '''Reduplication''', repeating all or part of a word to change its meaning;
* '''Alternation''', exchanging one sound for another in the root (usually vowel sounds, as in the ablaut / umlaut in <u>Germanic</u> languages);
* '''Suprasegmental''' variations, such as of '''stress''', '''pitch''' or '''tone''', where no sounds are added or changed but the intonation and relative strength of each sound is altered regularly.

==== Inflection and PIE Languages ====
Because the <u>Proto-Indo-European (PIE)</u> language was highly inflected, all of its descendants, such as <u>Albanian</u>, <u>Armenian</u>, <u>English</u>, <u>German</u>, <u>Ukrainian</u>, <u>Russian</u>, <u>Persian</u>, <u>Kurdish</u>, <u>Italian</u>, <u>Irish</u>, <u>Spanish</u>, <u>French</u>, <u>Hindi</u>, <u>Marathi</u>, <u>Urdu</u>, <u>Bengali</u>, and <u>Nepali</u>, are inflected to a greater or lesser extent. In general, ''older'' <u>Indo-European</u> languages such as <u>Latin</u>, <u>Ancient Greek</u>, <u>Old English</u>, <u>Old Norse</u>, <u>Old Church Slavonic</u> and <u>Sanskrit</u> are extensively inflected because of their temporal proximity to the PIE ancestor. 

'''Deflexion''' has caused ''modern'' versions of some <u>Indo-European</u> languages that were previously highly inflected to be much less so; an example is <u>English</u>, as compared to <u>Old English</u>. In general, languages where deflexion occurs replace inflectional complexity with more rigorous '''word order''', which provides the lost inflectional details.  However, the transition from '''synthetic''' (inflection-heavy) to '''analytic''' (relying more on word order and auxiliary words) is complex and can be influenced by multiple factors.

Most <u>Slavic</u> languages and some <u>Indo-Aryan</u> languages are an exception to the general <u>Indo-European</u> deflexion trend, continuing to be highly inflected (in some cases acquiring additional inflectional complexity and grammatical genders, as in <u>Czech</u> & <u>Marathi</u>).

=== Subordination and Coordination ===
These fundamental mechanisms by which clauses are combined in languages allow for the expression of complex ideas and relationships between events, actions, and descriptions. These mechanisms contribute to the '''grammatical hierarchy''' of sentences, determining how clauses are structured and integrated. 

'''Coordination''' joins two or more syntactic units of equal rank, such as words, phrases, or clauses, enabling them to function as a single unit. The coordinated elements can be seen as parallel or additive in nature.

* <u>Markers</u>: often marked by coordinating conjunctions ("and," "or," "but"). However, languages may also use non-conjunctive means, such as '''intonation''', '''punctuation''' (in written language), or even '''juxtaposition''' without explicit markers.
* <u>Symmetry and Balance</u>: typically share the same syntactic '''type''' (noun with noun, clause with clause) and contribute '''equally''' to the meaning of the sentence.
* <u>Functions</u>: allow for listing ('''enumeration'''), addition, choice, contrast, and other relational meanings between equally important ideas or actions.

'''Subordination''' involves embedding one clause (the subordinate or '''dependent''' clause) within another (the main or '''independent''' clause), creating a '''hierarchical relationship'''. The subordinate clause functions as a single unit within the larger structure, often specifying time, reason, condition, manner, or place.

* <u>Markers</u>: Subordination is marked in various ways, including subordinating conjunctions ("because," "if," "when"), relative pronouns ("which," "that," "whom"), or specific verb forms (subjunctive moods, non-finite verb forms). Some languages employ specific particles or changes in word order to indicate subordination.
* <u>Dependency</u>: The subordinate clause depends on the main clause for its interpretation, not being able to stand alone as a complete sentence. It typically provides additional information about an element in the main clause.
* <u>Types of Subordinate Clauses:</u> These include adverbial clauses (indicating time, reason, condition, etc.), relative clauses (modifying nouns), and complement clauses (serving as the object or subject of a verb or complement of an adjective or noun).

In a grammatical hierarchy, independent clauses rank higher than dependent clauses. Subordination allows for the embedding of clauses within clauses, leading to potentially complex sentence structures. This embeddedness is key to expressing nuanced and layered relationships between actions, events, and descriptions. Coordination and subordination can interact within a single sentence, with coordinated structures containing subordinate clauses, or with subordinate clauses themselves being coordinated, contributing to the syntactic and semantic complexity of language.

=== Sentence and Clause Structure ===
Although the specific grammatical tools and markers used to combine '''clauses''' can vary widely among languages, the concepts of simple, compound, complex, and compound-complex sentences offer a useful framework for analyzing sentence types from a language-agnostic perspective. 

==== Simple Sentences ====
A simple sentence consists of a single independent clause; it contains a subject and a predicate and expresses a complete thought. Simple sentences can be straightforward or can include multiple subjects, objects, or adjuncts, but they always revolve around a single main verb or verb phrase.

* [Subject] [Verb] [Object].
* The bird sings.

==== Compound Sentences ====
Compound sentences are formed by joining two or more independent clauses of equal status, meaning they could stand alone as simple sentences. The clauses in a compound sentence are typically connected by '''coordinating conjunctions''' (such as 'and,' 'but,' 'or') or by punctuation marks like semicolons in written language. The exact conjunctions or punctuation marks used can vary significantly across languages.

* [Independent Clause] <u>[Conjunction]</u> [Independent Clause].
* The bird sings <u>and</u> the cat meows.

==== Complex Sentences ====
Complex sentences consist of one independent clause and one or more '''dependent''' (or subordinate) clauses, which cannot stand alone as a sentence and is linked to the independent clause by '''subordinating conjunctions''' (like 'because,' 'since,' 'which') or '''relative pronouns''', depending on the language. The dependent clause adds information to the independent clause, specifying time, reason, condition, contrast, et cetera.

* [Independent Clause] <u>[Subordinating Conjunction]</u> [Dependent Clause].
* The bird sings <u>because</u> it is happy.

==== Compound-Complex Sentences ====
Compound-complex sentences combine elements of both compound and complex sentences; they include at least two independent clauses and one or more dependent clauses. These sentences are useful for conveying intricate relationships between ideas and combining multiple actions or situations.

* [Independent Clause] <u>[Conjunction]</u> [Independent Clause] ''[Subordinating Conjunction]'' [Dependent Clause].
* The bird sings, <u>and</u> the cat meows, ''because'' it is morning.

==== Considerations Across Languages ====
While these categories are helpful for analyzing sentence structure, it's important to recognize that languages may employ unique mechanisms for combining clauses:

* <u>Differential markings</u>: Some languages might use specific particles, verb forms, or word order changes to distinguish between independent and dependent clauses.
* <u>Conjunctions and connectors</u>: The exact words or particles used to connect clauses can vary widely, and some languages may use non-conjunctional means to indicate clause relationships.
* <u>Ellipsis and inference</u>: In some languages, elements of compound or complex sentences might be omitted if they can be inferred from context, making the sentence structure less explicit.

=== Syntactic Theories and Models of the 21st Century ===
Developed by '''Noam Chomsky''', <u>generative grammar</u> emphasizes the innate linguistic capability of humans and the idea of a '''universal grammar''' underlying all languages. It has evolved through various iterations:

* <u>Government and Binding (GB) Theory</u> was focused on the '''modular organization''' of syntax, including principles like <u>X-bar theory</u>, <u>case theory</u>, and <u>theta theory</u>.
* <u>Minimalist Program (MP)</u> aims to explain language using the minimal necessary theoretical constructs and principles, focusing on the economy of '''derivation''' and '''representation'''.

<u>Lexical-Functional Grammar</u> <u>(LFG)</u> emphasizes the importance of lexical information in determining grammatical structure and includes a distinction between functional structure ('''f-structure''') and constituent structure ('''c-structure''').

<u>Head-Driven Phrase Structure Grammar (HPSG)</u> focuses on the lexicon and complex feature-based descriptions, with a strong emphasis on the role of the '''head''' in phrase structure and a commitment to a '''non-transformational''' view of syntax.

<u>Categorial Grammar (CG)</u> is based on the idea that syntactic '''categories''' can be understood in terms of '''functions''' that combine words and phrases into larger units. Modern variants include <u>Combinatory Categorial Grammar (CCG)</u> and <u>Type Logical Grammar</u>.

<u>Dependency Grammar (DG)</u> centers on the '''dependency''' relation between headwords and their dependents as the primary structure organizing sentences, differing from '''phrase structure''' grammars by not assuming constituent phrases as primary.

<u>Construction Grammar (CxG)</u> argues that knowledge of language is based on '''constructions''', or '''form-meaning pairings''', that range from specific idioms to general grammatical patterns. Variants include ''Cognitive Grammar'' and ''Radical Construction Grammar''.

<u>Tree Adjoining Grammar (TAG)</u> is a highly lexicalized grammar framework that uses '''trees''' as the basic unit of syntax, allowing for more flexibility in describing cross-linguistic syntactic phenomena.

<u>Role and Reference Grammar (RRG)</u> integrates syntactic, semantic, and pragmatic information, focusing on the role of '''verb argument structure''' and the linking between semantic and syntactic roles.

<u>Optimality Theory (OT) for Syntax</u> was originally developed for phonology, but has been applied to syntax. It proposes that '''surface forms''' result from the competition between '''constraints''', rather than from transformational derivations.

<u>Dynamic Syntax (DS)</u> emphasizes the '''temporal dimension''' of syntax, modeling how sentences are processed in '''real-time''', focusing on the incremental building of semantic representations.

<u>Stochastic/Probabilistic Grammar</u> models incorporate '''probabilities''' into grammatical descriptions, often used in computational linguistics to model language understanding and production processes based on '''statistical patterns'''.

== Semantics ==
Put simply, semantics is the study of linguistic meaning. It evaluates how words get specific meanings, how the meaning of a complex combination-unit of grammar is dependent upon its constituent parts. The term derives from the Greek verb ''sēmainō'' (“to mean” or “to signify”), through the adjective ''sēmantikos'' (“significant”).

Natural languages (those that develop 'in the wild' among human populations) are known for being unboundedly productive; there is no upper limit in length, complexity, or number of grammatical expressions; Simpler expressions can be concatenated, relativized, complementized, et cetera to create ever-more-complex formulations. These complex expressions are both grammatically correct, and meaningful. 

In addition to '''compositionality''', semantic theories must also account for the phenomenon of reference. Reference is a characteristic of many expressions where the appearance of connection between words and the world seems quite unclear to outsiders by 'de jure meaning' (or sense) alone.  

=== Sense and Reference ===
In the philosophy of language, the distinction between '''sense''' and '''reference''' was an idea of the German philosopher and mathematician '''Gottlob Frege''' (''On Sense and Reference''; ''Über Sinn und Bedeutung''), reflecting the two ways he believed a singular term could have meaning.

* <u>Reference</u> (Bedeutung): The reference of a term is the object it refers to in the world. For example, the reference of the name "Venus" is the planet Venus itself.
* <u>Sense</u> (Sinn): The sense of a term is the way the reference is presented or the mode of presentation of the object. It involves the cognitive aspect of the term, how an individual conceives of the term's reference. For instance, "the morning star" and "the evening star" have the same reference (the planet Venus) but different senses, because they refer to Venus in different ways or contexts. The statement "the morning star is the evening star" is informative because it reveals that two different '''senses''' ("the morning star" and "the evening star") refer to the same object (Venus), even though the reference is the same.
The expressions ''triangular'' and ''trilateral,'' for example, are not <u>synonymous</u>, but there is no possible world in which they do not apply to exactly the same things. And the expression ''round square'' appears to be meaningful, but there is no possible world in which it applies to anything at all. Such examples are easy to multiply.

In semantics, '''truth''' is a property of statements that accurately present the world and '''true statements''' are in accord with reality. Whether a statement is true usually depends on the relation between the statement and the rest of the world; the truth conditions of a statement are the way the world needs to be for the statement to be true. For example, it belongs to the truth conditions of the sentence "it is raining outside" that raindrops are falling from the sky. The sentence is true if it is used in a situation in which the truth conditions are fulfilled: if there is actually rain outside.

The '''semiotic triangle''' is a model used to explain the relation between language, language users, and the world, represented in the model as ''Symbol'', ''Thought / Reference'', and ''Referent''. The '''symbol''' is a linguistic signifier, either in its spoken or written form. The central idea of the model is that there is no direct relation between a linguistic expression and what it refers to; this is expressed in the diagram by the dotted line between symbol and referent.

The model holds instead that the relation between the two is mediated through a third component (the thought or reference). For example, the term ''apple'' stands for a type of fruit but there is no direct connection between this string of letters and the corresponding physical object; the relation is only established indirectly through the mind of the language speaker. When they see this string of symbols or hear this string of phonemes, it evokes a mental image or a concept, which establishes the symbol's connection to the physical reference. This process is only possible if the speaker learned the meaning of the symbol previously; the meaning of a specific symbol is governed by the conventions of each specific language. 

=== '''Lexical relations''' ===
Describe how words stand to one another. Two words are <u>synonyms</u> if they share the same or a very similar meaning, like ''car'' and ''automobile,'' or ''buy'' and ''purchase''. <u>Antonyms</u> have opposite meanings, such as with ''alive'' and ''dead,'' or ''fast'' and ''slow''. One term is a <u>hyponym</u> of another if the meaning of the first is included in the meaning of the second (''ant'' is a hyponym of ''insect''). A <u>prototype</u> is a hyponym that has characteristic features of the type it belongs to (a ''robin'' is a prototype of a ''bird'' but a ''penguin'' is not). Two words with the same pronunciation are <u>homophones</u> like ''flour'' and ''flower'', while two words with the same spelling are <u>homonyms</u>, like a bank of a river in contrast to a bank as a financial institution. <u>Hyponymy</u> is closely related to <u>meronymy</u>, which describes the relation between part and whole. For instance, ''wheel'' is a meronym of ''car''. An expression is <u>ambiguous</u> if it has more than one possible meaning. The term <u>polysemy</u> is used if different meanings of a word are closely related to one another, like with the word ''head:'' the topmost part of the human body, or the top-ranking person in an organization.

=== Thematic roles ===
Also known as semantic roles, are conceptual categories that describe the relationship between a '''verb''' and its '''arguments''' (the entities involved in the action or state described by the verb). These roles help in understanding how different participants in a sentence are related to the action or state of the verb. 

The '''Agent''' is the <u>doer or initiator of an action</u>, typically a volitional entity that performs the action described by the verb. Agents are usually animate and capable of intentional actions. In the sentence "The chef cooked dinner," the chef is the Agent; the one performing the action of cooking.

The '''Patient''' is the entity that <u>undergoes the action</u> or the entity that is <u>affected by the action</u> of the verb. Patients are often the recipient of an action's effects and can be animate or inanimate. In "The chef cooked dinner," "dinner" is the Patient because it is being acted upon - it undergoes the action of being cooked.

The '''Theme''' is similar to the Patient in that it is <u>involved in</u> the action, but it is often used in a broader sense to include entities that are <u>being moved</u>, <u>experienced</u>, or otherwise <u>central to the action</u> without being <u>affected</u> in a manner that changes their state. The distinction between Patients and Themes can be subtle and, in some contexts, overlap; themes are central to the action, but not necessarily affected by it. In "She read a book," the book is the Theme - it is involved in the action of reading without undergoing a change.

The '''Experiencer''' is the entity that <u>perceives</u> or <u>feels an action</u> or state rather than physically carrying it out. This role is typically associated with mental states and perceptions. Experiencers are sentient, usually animate, and involved in actions or states in a '''non-volitional''' manner. In "She loves the painting," "she" is the Experiencer because she is the one having the feeling of love towards the painting.

=== Semantic Fields ===
Also known as semantic domains, are sets of words related by meaning within a specific area of experience or knowledge. Words within a semantic field share a common semantic property and are often interrelated in terms of the concepts they describe. Semantic fields illustrate how languages segment and categorize reality into distinct domains that reflect cultural and cognitive perspectives. Semantic fields encompass a broad range of lexical items, including nouns, verbs, adjectives, and adverbs, that relate to a common theme or subject area.

Words like "red," "blue," "green," etc., belong to the semantic field of <u>colors</u>. Terms such as "rain," "wind," "snow," "sunny," are part of the semantic field of <u>weather</u>. "Happy," "sad," "angry," "excited," are categorized within the <u>emotional</u> semantic field. Semantic fields are not only linguistic but also '''cultural constructs''', reflecting how a community's language and thought processes are influenced by its environment, social organization, and cultural practices.

=== Lexical Sets ===
A lexical set is a group of words within a language that are related by '''form''' or '''meaning'''. This concept is narrower than that of semantic fields and is often used in phonology to group words that share a particular phonetic or phonological feature, such as the same vowel sound; however, lexical sets can also be conceptualized based on semantic relationships, similar to semantic fields; usually in a more focused and specific way.

Lexical sets are primarily defined by linguistic criteria, whether phonological or semantic, and serve as a tool for analysis in linguistic studies. In <u>English</u> phonology, words like "trap," "bath," "palm," can be grouped into lexical sets based on their characteristic vowel sounds. Words pertaining to family relationships, like "mother," "father," "sibling," "cousin," can form a lexical set based on their semantic connections.

While both semantic fields and lexical sets deal with <u>groups of related words</u>, the distinction lies in their basis of categorization and their scope. Semantic fields are broader, categorizing words based on '''shared domains of meaning''' and reflecting how language maps onto human experience. Lexical sets, by contrast, are often defined by '''linguistic features''' (such as phonology) or narrower semantic criteria, serving specific analytical purposes in linguistics.

== Morphology ==
The internal construction of words from morphemes; some languages have highly complex morphology, while others (like <u>Vietnamese</u>) have very little, or even none. In linguistic '''typology''', languages are categorized based on how they use morphology to convey grammatical relationships. 

'''Inflectional morphology''' involves the <u>modification of a word</u> to express different grammatical categories such as tense, mood, voice, aspect, person, number, gender, and case. Inflection does not change the basic category or meaning of a word but rather adjusts it to fit its role within a sentence. 

Inflection conveys '''syntactic information''' necessary for the grammatical functioning of the word within a sentence. It helps in indicating '''relationships''' between different words in the sentence. The set of '''inflectional morphemes''' in a language is typically fixed or '''closed''', meaning that new inflectional morphemes are rarely added to the language. Inflectional processes are generally '''productive''', applying to nearly all words within the '''category''' they affect (though there can be irregular forms).

'''Derivational morphology''' involves <u>creating a '''new''' word</u> from an existing one by adding a '''prefix''' or '''suffix''' (or sometimes through other processes like '''internal change''' or '''compounding'''). Derivation alters the base word to create a new word with a related, but distinct, meaning (or it can place the word in a new grammatical category; noun to adjective, for example). 

New '''derivational morphemes''' can be added to the language over time (the set is '''open'''), and the process can give rise to an extensive variety of new words. Derivational processes vary in '''productivity'''; some apply broadly across many words, while others are restricted to a limited set of cases.

A fundamental difference between inflection and derivation is that inflection adjusts a word's form to fit grammatical constraints without changing its core meaning or category, whereas derivation changes the word's meaning and often its category as well. Inflectional changes result in different '''inflected forms''' of the same word, whereas derivational changes result in entirely new '''derived words'''. 

=== Analytic (Isolating) Languages ===
These languages tend to use a single morpheme (the smallest meaningful unit in a language) per word, meaning that they do not rely heavily on '''inflectional''' changes to indicate grammatical relationships. Instead, they often use word order, auxiliary words, and prepositions to convey grammatical relationships, tense, aspect, and other grammatical categories.

=== Synthetic Languages ===
These languages are characterized by a higher use of inflection or derivation to encode grammatical relationships within words. Synthetic languages can be further divided into:

'''Agglutinative''': morphemes (prefixes, suffixes, infixes, or circumfixes) are added to a base word in a relatively straightforward manner, with each morpheme typically representing a single grammatical category (such as tense, number, case, or aspect). These morphemes are easily separable and maintain consistent forms across different words. This cumulative process allows for a high degree of precision and clarity in expressing nuances of meaning and grammatical relationships. <u>Turkish</u>, <u>Finnish</u>, <u>Swahili</u>, and <u>Japanese</u> are examples.

'''Fusional (Inflectional)''': morphemes combine several grammatical categories such as gender, number, tense, mood, or case into a single affix attached to a word. This means that a single inflectional ending or internal modification in a word can convey multiple grammatical details. These languages tend to have a rich inventory of morphological forms. A single verb form can encode person, number, tense, aspect, and mood simultaneously. Unlike agglutinative languages, where morphemes have clear boundaries, fusional languages often exhibit forms where it's challenging to segment the word into discrete morphemes due to the merging of grammatical categories within a single affix. Languages like <u>Russian</u> and <u>Latin</u> fit here.

'''Polysynthetic''': multiple morphemes to express what might be conveyed in a full sentence in more analytic languages. These languages feature incorporation of nouns into verbs, allowing a single word to convey complex actions and relations. A single word can express what would require a full sentence in more analytic or even agglutinative languages. This includes incorporating subjects, objects, and relational information into one word. While agglutinative languages have clear morpheme boundaries and functions, polysynthetic languages often feature morphemes that blend together more fluidly, with less clear-cut distinctions between them. A single affix in a polysynthetic language might serve multiple grammatical or semantic roles. Examples include <u>Inuktitut</u>, <u>Yupik</u>, and <u>Mohawk</u>.

=== Affixation ===
A core morphological process used across languages to modify the meaning of a word or to adjust it for grammatical congruity. This process involves adding an '''affix''', a '''bound''' morpheme (that cannot stand alone) to a base word (or '''root'''). The base word can be simple form or another morphologically complex form; affixes can be categorized by their position relative to the base and the functions they perform.

==== Types of Affixes ====

* '''Prefixes''' are added to the beginning of a word. They can alter the meaning of the word or adapt it for grammatical purposes. The <u>English</u> prefix "un-" can be added to "happy" to form "unhappy."
* '''Suffixes''' attach to the end of a word. They are prevalent in indicating grammatical categories like tense, case, or number, as well as deriving new words. In <u>English</u>, adding "-ness" to "happy" creates "happiness."
* '''Infixes''' are inserted within the body of a word. Infixation is less common in <u>Indo-European</u> languages but is found in other language families, such as <u>Austronesian</u>. In <u>Tagalog</u>, the infix "-um-" can be inserted into "sulat" (write) to form "sumulat" (wrote).
* '''Circumfixes''' (or disfixes) attach to a base word in two parts, one at the beginning and one at the end. Circumfixation is seen in languages like <u>German</u>, where "ge-" and "-t" can enclose a verb to form a past participle, as in "gesagt" (said) from "sagen" (to say).

Affixation serves two primary functions: derivational and inflectional.

* '''Derivational Affixation''' creates new words with new meanings and often changes the grammatical category of the base. This process is crucial for expanding a language's vocabulary and can involve nuanced changes in meaning.
* '''Inflectional Affixation''' modifies a word to fit grammatical requirements without changing the word's essential meaning or category. It indicates grammatical relationships and features such as tense, number, gender, mood, and case. Inflectional affixation is more uniform and limited compared to derivational affixation.
The distinction between these two types of affixation is not always clear-cut; some languages use the same morphological process for both grammatical functions and lexical derivation, blurring the lines between the categories.

==== Affixation in Different Morphology Types ====
* <u>Agglutinative</u> languages tend to have a clear-cut, one-to-one correspondence between affixes and grammatical functions, stacking multiple affixes onto a base to express compound grammatical concepts.
* <u>Fusional</u> languages allow affixes to convey multiple grammatical categories simultaneously, and the form of the affix can change depending on the word it attaches to, leading to less transparent relationships between form and function.
* <u>Polysynthetic</u> languages can utilize extensive affixation, incorporating a large number of affixes into single, highly complex words that can express a great deal of information.

=== Reduplication ===
A morphological process involving the repetition of a whole or part of a word to convey grammatical functions or semantic nuances. This process can modify the meaning of the original word, indicate grammatical categories, or create new words, and can be partial or total, depending on whether part of the word or the entire word is repeated.

* '''Total Reduplication''': The entire word or root is repeated. This can serve various functions, such as pluralization, intensification, or aspectual distinctions.
** In <u>Indonesian</u>, "orang" (person) can become "orang-orang" to indicate "people" or a plurality of persons.
* '''Partial Reduplication''': Only a segment of the word, such as a syllable or a set of phonemes, is duplicated. Partial reduplication can be used to denote diminutives, verb tenses, and other grammatical or semantic changes.
** In <u>Tagalog</u>, "ganda" (beauty) can be reduplicated as "maganda" (beautiful) by partially repeating the first syllable and adding it as a prefix.

Reduplication serves a variety of linguistic functions, which can differ widely among languages:

* Grammatical Aspect: Indicating completed, habitual, ongoing, or iterative actions.
* Tense: Marking past, present, or future tense in verbs.
* Mood: Showing mood such as indicative, imperative, or subjunctive.
* Number: Distinguishing singular from plural or dual.
* Intensity or Degree: Signaling intensity, emphasis, or degree of an adjective or adverb.
* Diminutive, Augmentative, or Pejorative Meaning: Modifying nouns or adjectives to convey size, importance, or emotional tone.
The function of reduplication can also extend to creating '''onomatopoeic''' expressions or '''mimetic''' words, which is common in some languages to imitate sounds or describe movements and appearances.

=== Compounding ===
A morphological process involving the combination of two or more '''lexemes''' (independent words) to form a <u>new word</u>. The resulting '''compound word''' typically acquires a meaning that is distinct from, but related to, the meanings of its constituent parts. Compounds can be formed from various combinations of parts of speech, including nouns, adjectives, verbs, and adverbs, among others.

* Two '''nouns''' are combined to form a new noun. For example, "toothbrush" (tooth + brush) or "bookcase" (book + case).
* An '''adjective''' and a '''noun''' are combined, usually to describe a specific type of the noun. Examples include "blackboard" (black + board) or "greenhouse" (green + house).
* A '''verb''' and a '''noun''' are combined, often describing an action related to the noun. For instance, "pickpocket" (pick + pocket).
* Two '''verbs''' are combined to describe actions that are done together or in sequence. This is less common in some families but can be seen in some <u>South Asian</u> languages.

The compound often represents a concept or entity that is <u>semantically unified</u>, which means its overall meaning cannot always be directly inferred from the meanings of its parts. Compounding can involve <u>morphological</u> changes (such as the modification of roots) or <u>phonological</u> changes (such as stress shifts) to mark the compound status, or aid in pronunciation. Once words are compounded, the new formation behaves as a single unit syntactically. It takes on the grammatical roles as one word, and its internal structure is not affected by syntactic operations that affect phrases.

Compounds typically have a '''head''', the part that determines the overall category and grammatical properties of the compound. The position of the head varies across languages; for example, in <u>English</u>, the head is usually on the right ("toothbrush" is a type of brush), whereas in <u>Japanese</u>, it is typically on the left (電話 "denwa," phone, is literally "electric + talk").

'''Endocentric compounds''' have a head that provides the compound with its basic meaning and category ("blueberry" is a type of berry). '''Exocentric compounds''' lack a clear head, and the compound does not belong to the category of any of its parts ("pickpocket" is not a type of pocket). The rules governing compounding and the productivity of this process vary widely among languages; some are highly compounding, creating many new words through this process, while others use it much more sparingly.

The semantic relationship between components of a compound can vary greatly and is often not explicitly marked, which can lead to a wide range of interpretations based on cultural or contextual knowledge.

=== Suppletion ===
This concept represents an '''irregular''' way to form word variants, such as different tenses of a verb or comparative and superlative forms of an adjective. Unlike regular morphological processes that add, modify, or replace affixes while keeping the base of the word recognizable, suppletion involves using ''entirely different roots'' to express grammatical or semantic relations. This process results in word forms that cannot be predicted from the form of the base word and must be memorized as separate lexical entries.

Suppletion is highly irregular and constitutes an exception to the normal morphological rules of a language. The suppletive forms bear no phonological or morphological resemblance to their base forms. It is therefore relatively rare and typically affects a small set of commonly used words within a language: often verbs, adjectives, and pronouns. Despite its irregularity, suppletion serves regular grammatical functions, such as tense, number, or degree of comparison.

One of the most well-known examples is the verb "to go" in <u>English</u>, which forms its past tense as "went," a word originally derived from the <u>Old English</u> verb "wendan" (to turn). Thus, "go" and "went" demonstrate suppletion. The adjectives "good," "better," and "best" in <u>English</u> show suppletion, where "better" and "best" do not derive from "good" through regular morphological processes. In many languages, '''personal pronouns''' exhibit suppletion. For example, in <u>English</u>, the forms "I," "me," "my," and "mine" are related through meaning and function but not through form.

Suppletion is found across a wide range of languages, indicating that it is a common, though irregular, linguistic phenomenon:

* <u>Latin</u>: "To be" shows suppletion with "sum," "es," "est" (present) and "fui" (perfect).
* <u>Spanish</u>: "To go" is "ir," but its future stem is "ir-" and the past stem is "fu-," as in "fui" (I went).
* <u>Russian</u>: "To go" has "идти" (idti) in the present tense and "пойти" (pojti) in the future tense.

Suppletion is often explained as the result of '''historical linguistic evolution''', where words from different etymological sources merge over time due to similar meanings or functions. These changes are usually driven by frequent use, '''phonological erosion''', and the natural tendency for languages to '''regularize''' irregular forms, leaving only a few highly irregular suppletive forms. Linguists study suppletion to understand language change and the balance between irregularity and the drive for regular grammatical patterns. Suppletion often arises historically from different '''lexical sources''' merging into the grammatical system of a language.

=== Conversion ===
Also known as '''zero derivation''' or '''functional shift''', conversion is a morphological process through which a word is reassigned to a new grammatical '''category''' without the addition of an affix or any change to its form. This process allows a word from one part of speech, such as a noun, to function as another part of speech, like a verb, simply through a shift in its grammatical '''context'''. Conversion allows languages to expand their lexical and functional capacity, often creating pairs of related words that differ in grammatical category but are identical in form.

Unlike other morphological processes, conversion involves no alteration to the word's spelling or phonetics; the change in grammatical function is indicated solely by the word's use in context. Conversion can occur in multiple directions, such as noun to verb, verb to noun, adjective to noun, et cetera. It is a highly '''productive''' means of word formation in many languages, allowing for the rapid creation of new words to meet communicative demands.

* <u>Noun to Verb</u>: The use of a noun in a verbal context, thereby creating a verb with a related meaning. For example, "to bottle" (from "bottle," implying the action of putting something into bottles).
* <u>Verb to Noun</u>: The use of a verb as a noun, often referring to the act or instance of performing the verb. An example might be "a run" (from "to run," referring to a single act of running).
* <u>Adjective to Verb</u>: The transformation of an adjective into a verb, enabling the description of the action of becoming or making something have the quality of the adjective. For instance, "to empty" (from "empty," meaning to make something empty).

=== Cliticization ===
A morphological and phonological process involving '''clitics''', grammatical elements that possess syntactic characteristics of words but behave phonologically like affixes. Clitics are dependent on adjacent words for their pronunciation and often cannot stand alone, lacking the stress patterns typical of full words.

They require a '''host''' word to attach to, as they cannot independently bear stress; unlike affixes, which are bound to specific parts of speech, clitics can attach to various categories of words. They often encode grammatical functions such as negation, possession, articles, pronouns, or auxiliary verbs. '''Proclitics''' attach to the beginning of a host word; '''enclitics''' attach to the end of a host word; '''mesoclitics''' are inserted ''within'' a host word. 

In <u>Romance</u> languages like <u>Spanish</u> and <u>Italian</u>, object pronouns often appear as clitics attached to verbs. In <u>Italian</u>, "lo" (it) can attach to "vedo" (I see) to form "lo vedo" (I see it). In <u>English</u>, the possessive "'s" is considered a clitic that can attach to noun phrases to indicate possession, as in "the king of Spain's crown." In <u>Greek</u>, the definite article can act as a proclitic, attaching to the beginning of the word it modifies. In <u>French</u>, "ne" in the negation "ne...pas" behaves like a clitic, attaching to auxiliary or main verbs to form negatives, as in "Je ne sais pas" (I don't know).

Distinguishing clitics from affixes can be challenging but important. Affixes are inherently '''bound morphemes''' that <u>directly modify the meaning or grammatical category</u> of the words they attach to and are <u>restricted to specific lexical categories</u>. Clitics, while also bound in '''pronunciation''', retain a syntactic identity separate from the host and can often attach to a broader range of categories.

Clitics pose a significant challenge for linguistic analysis and language learning, as their behavior intersects morphology and syntax, sometimes leading to debates and confusion about their classification or use.

==== Word Categories ====
Also known as '''parts of speech''', are fundamental classes into which words are grouped based on their functions in sentences. While the specific categories can vary slightly from language to language, there are broad categories that are widely recognized across languages.

* '''Nouns''' are words that name <u>entities</u>: people, places, things, concepts, or ideas. They can serve as the subject or object of a verb and can often be modified by adjectives. There are many ways to categorize nouns, depending on the specifics of a given language. 
** '''Common nouns''' refer to general items, beings, or concepts without specifying particular individuals or entities. Examples include "city," "dog," "happiness."
** '''Proper nouns''' name specific individuals, places, organizations, or sometimes events, and are usually capitalized in writing. Examples include "Paris," "Amazon River," "World War II."
** '''Countable''' '''nouns''' can be counted and have both singular and plural forms; they can be used with numbers or quantifiers like "many," "few." Examples: "apple," "car."
** '''Uncountable (mass) nouns''' refer to substances, concepts, or masses that cannot be easily counted and typically do not have a plural form. They are used with quantifiers like "much," "little." Examples: "water," "sand," "information."
** '''Concrete nouns''' name things that can be observed through the senses; they refer to physical objects and substances. Examples: "tree," "music."
** '''Abstract nouns''' represent ideas, qualities, or concepts that cannot be physically touched or seen. Examples: "freedom," "beauty," "time."
** '''Collective nouns''' refer to groups of individuals or things as a single entity. Examples include "team," "flock," "family." The grammatical number (singular or plural) these nouns take can vary by language and context.
** '''Agent nouns''' indicate the doer of an action, often derived from verbs. Examples: "writer" (from "write"), "teacher" (from "teach"). They specify who or what is performing an action.
** '''Gendered nouns''' have grammatical gender (masculine, feminine, neuter, or others), affecting agreement with adjectives, determiners, and sometimes verb forms. Examples: In Spanish, "amigo" (male friend) vs. "amiga" (female friend); in German, "Mädchen" (girl) is neuter.
** '''Animacy''' classify nouns based on whether they are animate (living) or inanimate (non-living), which can affect verb agreement, case marking, or article usage.
** '''Pronominal nouns''' overlap with pronouns in some languages, especially in addressing or referring to people with certain social roles or relationships.

* '''Pronouns''' are words that take the place of nouns or noun phrases, often to avoid repetition. There are a number of subcategories:
** '''Personal pronouns''' replace specific nouns that denote people or things and often distinguish by person (first, second, third), number (singular, plural), and sometimes gender. They can act as subjects or objects within sentences. Examples: I, you, he, she, it, we, they.
** '''Possessive pronouns''' indicate ownership or possession. They can stand alone, replacing a noun phrase, and often reflect the same distinctions as personal pronouns (person, number, gender). Examples: mine, yours, his, hers, its, ours, theirs.
** '''Reflexive pronouns''' are used when the subject and the object of a verb are the same entity, indicating that the action of the verb is directed back at the subject. Examples: myself, yourself, himself, herself, itself, ourselves, yourselves, themselves.
** '''Demonstrative pronouns''' point to specific nouns, distinguishing them based on their location relative to the speaker (near or far). They often differentiate between singular and plural forms. Examples: this, that, these, those.
** '''Interrogative pronouns''' are used to ask questions about people or things; they typically introduce question clauses. Examples: who, whom, whose, which, what.
** '''Relative pronouns''' introduce <u>relative clauses</u>, which provide additional information about a noun without starting a new sentence. They relate the clause to a noun or pronoun in the main clause. Examples: who, whom, whose, which, that.
** '''Indefinite pronouns''' refer to nonspecific people or things; they are often used to make general statements or to refer to an unspecified subset of a group. Examples: anyone, everybody, someone, something, nothing, neither.
** '''Reciprocal pronouns''' are used to indicate a mutual or reciprocal action or relationship among the participants mentioned in the subject of the clause. Examples: each other, one another.
** '''Intensive pronouns''', also known as '''emphatic pronouns''', are used to add emphasis to a noun or pronoun that has already been mentioned. They often mirror the form of reflexive pronouns but serve a different function. Examples: myself, yourself, himself, herself, itself, ourselves, yourselves, themselves (used for emphasis).
** '''Quantitative pronouns''' indicate an amount or quantity, referring to a number or quantity of something. Examples: all, some, any, none, few, many, much.

* '''Verbs''' are words that express <u>actions</u>, <u>states</u>, or <u>occurrences</u>. They are central to predicate constructions and can be modified in terms of tense, aspect, mood, and voice to convey different temporal, modal, and voice relationships.
** '''Main verbs''' carry the core semantic content of a sentence. They express actions, states, or processes. Examples: run, think, exist, become.
** '''Auxiliary verbs''' are used together with a main verb to form verb phrases, contributing functional meaning related to tense, aspect, mood, or voice. Examples: be (is, am, are), have, will, shall, do.
** '''Modal verbs''' are a subset of auxiliary verbs that express modality - possibility, necessity, permission, or ability. Examples: can, could, may, might, must, shall, should, will, would.
** '''Transitive verbs''' require a direct object to complete their meaning, indicating actions that affect something or someone. Examples: eat, read, want.
** '''Intransitive verbs''' do not take a direct object, often describing actions or states that do not act upon something else. Examples: sleep, arrive, exist.
** '''Ditransitive verbs''' take two objects (a direct and an indirect object), typically involving an action where something is given or communicated to someone. Examples: give, send, tell.
** '''Linking verbs''' connect the subject of a sentence to a subject complement, which can be a noun or an adjective that describes or identifies the subject. Examples: be, seem, become, appear.
** '''Phrasal verbs''' consist of a verb and one or more particles (prepositions or adverbs), where the combination creates a meaning different from the individual parts. Examples: look up, break down, put off.
** '''Dynamic verbs''' describe actions, processes, or activities that have duration and can be perceived by the senses. Examples: write, jump, grow.
** '''Stative verbs''' describe states or conditions rather than actions, often relating to thoughts, emotions, relationships, senses, or possession. Examples: love, know, belong, need.
** '''Reflexive verbs''' are those where the subject and the object are the same entity, and the action is directed back at the subject. Examples: (in languages like Spanish or French) se lavar (to wash oneself), se regarder (to look at oneself).
** '''Reciprocal verbs''' indicate actions or states that are shared mutually by two or more subjects. Examples: meet (as in "They met each other"), hug.
** '''Causative verbs''' indicate that the subject causes someone or something else to do or be something. Examples: make, let, have (in the sense of causing someone to do something).
** '''Irregular verbs''' do not follow the standard rules of verb conjugation in a language. Examples: go/went/gone, be/was/were.

* '''Adjectives''' are words that <u>describe</u> or <u>modify</u> nouns, providing additional information about qualities, quantities, or characteristics. They can often be used comparatively and superlatively ("big," "bigger," "biggest").
** '''Descriptive adjectives''' provide specific information about the qualities or characteristics of nouns, such as color, size, shape, taste, or emotion. They are the most common type of adjectives and can usually be graded (comparative and superlative forms). Examples: red, tall, bitter, happy.
** '''Quantitative adjectives''' indicate an exact or approximate quantity of the noun they modify. They can refer to numbers, amounts, or degrees of comparison. Examples: three, many, few, several.
** '''Demonstrative adjectives''' specify particular nouns in terms of proximity or location relative to the speaker or within a narrative context. They often distinguish between near and distant entities. Examples: this, that, these, those.
** '''Possessive adjectives''' denote ownership or association with the noun. They are related to possessive pronouns but are used attributively before a noun. Examples: my, your, his, her, its, our, their.
** '''Distributive adjectives''' refer to members of a group individually rather than collectively. They often denote division or allocation. Examples: each, every, either, neither.
** '''Interrogative adjectives''' are used to ask questions about nouns, typically regarding their identity, quantity, or quality. They modify nouns in interrogative sentences. Examples: which, what, whose.
** '''Indefinite adjectives''' provide nonspecific information about a noun, often referring to an unspecified element within a broader set or category. Examples: some, any, few, several, many.
** '''Ordinal adjectives''' indicate the position or order of a noun in a sequence. They are often derived from cardinal numbers. Examples: first, second, third, last.
** '''Proper adjectives''' are derived from proper nouns and are typically used to denote a specific relation to a person, place, or entity. They are usually capitalized. Examples: Victorian (era), Shakespearean (drama), American (culture). 
** '''Predicate adjectives''' appear in the predicate of a sentence and are linked to the subject by a copula or linking verb, describing the subject's state or condition. Examples: "The sky is blue," where "blue" is a predicate adjective describing "sky."
** '''Attributive adjectives''' directly modify a noun and are usually placed before the noun they describe in English, although the position can vary in other languages. Examples: "A cold wind," where "cold" is an attributive adjective modifying "wind."
** '''Comparative and Superlative adjectives''' express degrees of comparison - comparative adjectives compare two entities, and superlative adjectives denote the extreme degree among three or more entities. Comparative Example: taller (than). Superlative Example: tallest.

* '''Adverbs''' <u>describe</u> or <u>modify</u> verbs, adjectives, other adverbs, or entire sentences, typically providing information about manner, place, time, frequency, degree, or circumstance ("quickly," "very," "yesterday").
** '''Manner adverbs''' describe how an action is performed, answering the question "How?" Examples: quickly, slowly, carefully, easily.
** '''Time adverbs''' indicate when an action occurs, its duration, or its frequency.
*** '''Definite time adverbs''' specify exact times. ''Examples'': today, yesterday, tomorrow, now, then.
*** '''Indefinite time adverbs''' indicate general or relative times. ''Examples'': always, never, often, sometimes, frequently.
** '''Duration adverbs''' describe how long an action lasts. ''Examples'': all day, for a year, momentarily.
** '''Frequency adverbs''' describe how often an action occurs. ''Examples'': weekly, monthly, annually.
** '''Place adverbs''' specify the location or direction of an action or state, answering "Where?" Examples: here, there, everywhere, nowhere, inside, outside, upstairs.
** '''Degree adverbs''' modify adjectives, verbs, or other adverbs to indicate the intensity or extent of an action or quality, answering "How much?" or "To what extent?" Examples: very, quite, almost, too, entirely, just, enough.
** '''Cause or Reason adverbs''' explain why an action is performed or why a state exists. Examples: therefore, hence, thus, consequently.
** '''Condition adverbs''' set up a conditional relationship or circumstance for the action or state to occur. Examples: otherwise, provided, unless.
** '''Conjunction adverbs''', also known as conjunctive adverbs, they connect clauses or sentences, indicating a relationship like addition, contrast, or cause and effect. Examples: however, moreover, therefore, nonetheless, consequently.
** '''Affirmation and Negation adverbs''' either affirm or negate the action or state described by the verb. Examples of Affirmation: certainly, indeed, surely. Examples of Negation: not, never, no.
** '''Interrogative adverbs''' are used to ask questions about time, place, manner, or degree. Examples: when, where, why, how.
** '''Focus adverbs''' draw attention to a particular element of the sentence. Examples: even, only, also, especially.
** '''Viewpoint adverbs''' provide information about the speaker's attitude or perspective towards the action, often relating to the certainty or evidentiality of the statement. Examples: apparently, possibly, presumably, obviously.

* '''Prepositions''' are words that <u>express relationships</u> between other words, typically indicating spatial, temporal, or other semantic relationships. They usually precede a noun or pronoun to form a prepositional phrase ("in," "on," "at," "before").
** '''Spatial prepositions''' indicate the location or position of something in relation to another object. Examples: at, on, in, under, over, beside, between, behind, near.
** '''Temporal prepositions''' specify when something happens or the duration of an event. Examples: at, on, in, before, after, during, since, until, by.
** '''Directional prepositions''' describe the direction or path of movement. Examples: to, toward, into, out of, from, up, down, through, across.
** '''Instrumental prepositions''' indicate the means or instrumentality by which an action is performed. Examples: by, with, using, via.
** '''Causal prepositions''' express reasons or causes. Examples: because of, due to, owing to, thanks to.
** '''Possessive prepositions''' show possession, ownership, or belonging. Examples: of, with.
** '''Agency prepositions''' are used to indicate the agent (doer) in passive constructions. Examples: by, with.
** '''Comparative prepositions''' are used to compare two entities in terms of quality, quantity, or degree. Examples: like, as, than.
** '''Comitative prepositions''' express companionship or accompaniment. Examples: with, alongside, together with.
** '''Benefactive prepositions''' indicate for whom or for whose benefit an action is performed. Examples: for, for the sake of.
** '''Purpose prepositions''' express the purpose or intent of an action. Examples: for, to.

* '''Conjunctions''' are words that <u>link</u> clauses, sentences, words, or phrases, coordinating them ("and," "but," "or") or subordinating one clause to another ("because," "although," "if").
** '''Coordinating conjunctions''' connect words, phrases, or clauses that are equal or similar in structure and importance. They can link various parts of speech or entire sentences, ensuring grammatical consistency between the connected elements. Examples: and, but, or, nor, for, yet, so. Subtypes include:
*** '''Cumulative Conjunctions''' add elements without implying a priority or sequence ("and").
*** '''Adversative Conjunctions''' indicate contrast or opposition ("but," "yet").
*** '''Disjunctive Conjunctions''' present alternatives or choices ("or").
*** '''Causal Conjunctions''' provide reasons or explanations ("for").
** '''Subordinating conjunctions''' connect dependent clauses to independent clauses, indicating a relationship such as time, place, reason, condition, concession, comparison, or purpose between them. The subordinate clause typically provides additional information that completes or elaborates on the main clause. Examples: because, if, although, while, since, until, when, where, as. Subtypes are often named after the specific relationship they indicate, such as:
*** '''Time Conjunctions''' indicate when something happens ("when," "while").
*** '''Cause and Effect Conjunctions''' establish a cause-effect relationship ("because," "since").
*** '''Condition Conjunctions''' set conditions ("if," "unless").
*** '''Concession Conjunctions''' introduce a concessive statement, expressing a contrast with what would be expected ("although," "even though").
*** '''Comparison Conjunctions''' make comparisons ("than," "as...as").
** '''Correlative conjunctions''' are pairs of conjunctions that work together to link equivalent elements in a sentence; they often add emphasis or a sense of balance to the sentence structure. Each element in the pair introduces part of the sentence that is to be linked, ensuring that the connected elements are seen as equally significant. Examples: either...or, neither...nor, not only...but also, both...and, whether...or.
** While not traditional conjunctions, '''conjunctive adverbs''' function similarly by connecting independent clauses; they provide transitions between ideas, indicating relationships such as contrast, sequence, cause and effect, or emphasis. Conjunctive adverbs are typically followed by a semicolon or a comma. Examples: however, therefore, moreover, consequently, then, otherwise. 

* '''Interjections''' are words or phrases that <u>express strong emotion or reaction</u>, often standing alone ("Wow!," "Oh no!," "Hey!"). They are typically punctuated with an exclamation point in writing.
** '''Emotional interjections''' express a specific emotional response, such as surprise, happiness, sadness, or anger.
*** Surprise: "Wow!", "Oh!"
*** Happiness: "Yay!", "Hooray!"
*** Sadness: "Alas!", "Oh no!"
*** Disgust: "Ugh!", "Ew!"
** '''Greeting interjections''' are used to greet someone or acknowledge their presence. Examples: "Hello!", "Hey!", "Hi!"
** '''Farewell interjections''' are used to bid someone goodbye. Examples: "Bye!", "Farewell!", "See ya!"
** Agreement or '''acknowledgement interjections''' express agreement or acknowledgment of what someone has said. Examples: "Okay!", "Yes!", "Uh-huh!"
** Hesitation or '''pause interjections''' are used to indicate a speaker's hesitation, thinking process, or a brief pause in dialogue. Examples: "Um...", "Uh...", "Er..."
** '''Attention-getting interjections''' serve to capture someone's attention or to call out. Examples: "Hey!", "Yo!", "Psst!"
** Pain or '''distress interjections''' express physical pain or emotional distress. Examples: "Ouch!", "Ow!", "Agh!"
** '''Call to action interjections''' urge someone to take immediate action or express encouragement. Examples: "Go!", "Hurry up!", "Come on!"
** '''Sound imitative interjections''' mimic specific sounds or noises. Examples: "Bang!", "Woof!", "Meow!"
** '''Fillers''' are used to fill in gaps in speech, often without adding any specific meaning. Examples: "Well...", "You know...", "Like..."

* '''Articles''' and '''determiners''' function to <u>specify or quantify</u> nouns. Articles ('''definite''' and '''indefinite''') identify the noun in a specific or nonspecific manner ("the," "a," "an" in <u>English</u>), while determiners can indicate possession, quantity, or identity ("some," "my," "each").
* '''Particles''' are <u>function words</u> that do not fit neatly into the other categories and can have various grammatical or pragmatic functions, including <u>modal</u> nuances, <u>aspectual</u> markers, or forming <u>phrasal verbs</u>. Their classification and function can vary significantly across languages.

In some languages, the boundaries between categories can be '''fluid'''. In certain contexts, words traditionally classified as one part of speech might function as another, blurring the lines between categories. Some languages have word categories not commonly found or not as prominently featured in others. Some languages distinguish between '''inclusive''' and '''exclusive''' "we" in their pronoun systems; or they might have a special set of verb forms used only in certain social contexts ('''honorifics''').

Certain languages use a significant number of '''particles''' to convey grammatical relationships or pragmatic meanings that don't easily fit into the categories listed. These can include '''discourse''' markers, '''evidentials''' (which indicate the source of the speaker's knowledge), and other language-specific particles that serve various functions. Some languages, especially those in <u>East Asia</u>, use classifiers or counter words in conjunction with numerals to count nouns, classify nouns, or indicate noun types. These could be considered a separate category due to their specific syntactic and semantic functions.

== Case Systems ==
Case systems organize how nouns and their related words (pronouns, adjectives) connect to verbs and other sentence elements, indicating their grammatical roles (such as subject, object, et cetera). '''Transitive''' and '''intransitive''' verbs are categories that describe how verbs interact with objects within sentences. The distinction between them is foundational in understanding sentence structure and grammar across languages. 

Transitive verbs require one or more '''objects''' to complete their meaning; they express <u>actions</u> that are done <u>to</u> someone or something. The object of a transitive verb receives the action of the verb. In the sentence "She reads a book," "reads" is a transitive verb because the action is being performed on an object, "a book." 

Intransitive verbs are verbs that do not take an object; their meaning is complete without needing to express an action being performed on someone or something. Intransitive verbs often describe actions, states of being, or occurrences that involve only the subject. In the sentence "He sleeps," "sleeps" is an intransitive verb because there is no object receiving the action; the verb simply describes the subject's state or action.

Some verbs can be both transitive and intransitive, depending on their use in a sentence; they are known as '''ambitransitive''' verbs. For example, "to eat" can be used transitively as in "She eats an apple" or intransitively as in "She eats quickly." While transitive verbs require direct objects to complete their meaning, some intransitive verbs can be followed by other types of '''complements''' (like adverbials or prepositional phrases) that provide additional information but do not receive the action of the verb.

A subtype of transitive verbs, '''ditransitive''' verbs, require <u>two</u> objects (direct ''and'' indirect) to complete their meaning, as in "She gave her friend a gift," where "gave" is the ditransitive verb, "her friend" is the indirect object, and "a gift" is the direct object.

=== Nominative-Accusative ===
In these language systems, the <u>subject</u> of both transitive and intransitive verbs is marked by the <u>nominative case</u>, and the <u>object</u> of transitive verbs is marked by the <u>accusative case</u>. This alignment emphasizes the action's '''agent''', regardless of the verb's '''transitivity'''. This system is the most common type of alignment; many <u>Indo-European</u> languages, such as <u>English</u>, <u>Spanish</u>, and <u>Russian</u>, primarily use nominative-accusative alignment, although in <u>English</u>, case marking is largely restricted to personal pronouns ("I" versus "me").

=== Ergative-Absolutive ===
These languages mark the subject of an intransitive verb in the same way as the <u>object</u> of a transitive verb - both in what's called the '''absolutive''' '''case''' - while the <u>subject</u> of a transitive verb is marked differently, in the '''ergative case'''. This alignment emphasizes the action's undergoer or the participant most directly affected by the action. Languages such as <u>Basque</u>, <u>Georgian</u>, and many <u>Australian Aboriginal</u> languages exhibit ergative-absolutive alignment.

=== Split Ergativity ===
A system where both '''nominative-accusative''' and '''ergative-absolutive''' alignments are used, under different conditions. These conditions can be based on grammatical factors such as tense, aspect, or the person of the subject, or on semantic factors like the nature of the verb or its participants. Languages with split ergativity include <u>Georgian</u>, where the split is based on the verb's tense or aspect, and <u>Hindi-Urdu</u>, which shows ergative behavior in perfective aspects of certain verbs.

=== Tripartite ===
Where the subject of an intransitive verb, the subject of a transitive verb, and the object of a transitive verb each receive different '''case markings'''. This is relatively rare among the world's languages, as it requires a clear and distinct marking for each of these roles:

* <u>Nominative case</u> marks the subject of intransitive verbs.
* <u>Accusative case</u> marks the object of transitive verbs.
* <u>Ergative case</u> marks the subject of transitive verbs.

This system provides a clear distinction between subjects acting upon objects and subjects acting alone. An example of a language with a tripartite alignment is <u>Nez Perce</u>, spoken in the Pacific Northwest of the United States.

=== Active-Stative ===
Languages of this system categorize <u>subjects</u> based on whether they are '''agents''' (performers of an action) or '''patients''' (recipients of an action). Unlike nominative-accusative or ergative-absolutive systems that categorize based on transitivity, active-stative systems allow the verb's subject to be marked differently based on semantic roles, even in intransitive sentences.

In '''Split-S''' languages there is a consistent rule for marking subjects of intransitive verbs as either agents or patients, based on the verb or the verb's semantics. In '''Fluid-S''' languages, the marking depends on the verb's semantics or the speaker's perspective. A verb like "to run" might mark its subject as an agent in one context but as a patient in another, depending on whether the running is '''volitional'''. 

=== Direct-Inverse ===
This system typifies some indigenous languages of the <u>Americas</u>, and marks the direction of the action in terms of the '''hierarchy of participants''' (often based on animacy or topicality). A '''direct''' marking indicates that the action follows the <u>expected hierarchy</u> (a higher-ranking agent acting on a lower-ranking patient), while an i'''nverse''' marking shows that the action goes <u>against</u> the expected hierarchy.

=== Differential Object Marking (DOM) ===
DOM is a related phenomenon where the <u>object</u> of a verb is marked differently based on specific semantic or pragmatic factors, such as definiteness, animacy, or specificity. This can sometimes blur the lines with '''accusative''' systems but serves different functions by highlighting certain features of the direct object.

=== Austronesian Alignment ===
This system, found in many <u>Austronesian</u> languages, features a unique way of marking the focus of a sentence through '''voice''' or '''trigger'''. Rather than focusing on the agent or patient inherently, the language can <u>mark</u> which participant is the focus of a given clause, affecting verb morphology.

=== Semantic Role-Based ===
Some languages employ case marking systems that are more directly tied to the '''semantic roles''' of participants, such as <u>experiencer</u>, <u>benefactive</u>, or <u>instrument</u>, rather than or in addition to their '''syntactic roles'''. 

=== Fusion between Systems ===
Some languages exhibit features of more than one alignment system, demonstrating the fluidity of case roles and grammatical structures across languages. Case systems can change over time within a language, contributing to the development of mixed or evolving alignments. Historical linguistics often studies these changes to understand language evolution. The '''functional load''' of case markings can vary widely, with some languages relying heavily on case to indicate grammatical relations and others using word order or auxiliary words for the same purpose.

== Tense, Aspect, and Mood (TAM) ==

=== Tense ===
Conveys when an action happens from the speaker's perspective, relating the <u>position in time</u> of the action; a specific point in the past or future, or, in some languages, even extending to the speaker's perspective on the flow of time itself.

* '''Past''': Indicates actions or states that occurred before the moment of speaking. It can be further subdivided into categories like simple past, past continuous, past perfect, and past perfect continuous, among others, depending on how specific languages conceptualize the flow of time and action.
* '''Present''': Describes actions or states occurring at the moment of speaking, or general truths that are timeless. It can also encompass habitual actions or states that are not necessarily happening at the moment but occur regularly.
* '''Future''': Refers to actions or states that are expected to occur after the moment of speaking; future tense can have subdivisions that provide additional nuances regarding the future action's certainty, immediacy, or manner of occurrence.

Some languages extend tense beyond these basics to express a wide range of temporal nuances:

* '''Remote versus Recent/Near''': differentiate between actions that happened a long time ago versus those that occurred more recently; or those that will occur in the remote future versus those that will occur in the near future. 
* '''Imperfect versus Perfect''': imperfect tense refers to actions that were ongoing or not completed in the past, while the perfect tense indicates actions that were completed in the past and have relevance to the present.
* '''Aorist''': in some languages, the aorist tense describes actions without specifying whether they are completed or ongoing, focusing instead on the fact that an action simply occurs.

=== '''Aspect''' ===
Focuses on the internal structure of an action (how it <u>unfolds over time</u>) rather than its <u>position in time</u>; it allows speakers to provide insights into the process, completion, repetition, or duration of a described action. 

* '''Perfective''' aspect indicates that an action is viewed as a complete whole, without focusing on its internal structure. Perfective aspect often implies that the action has been completed, especially when referring to past actions, and is used to express a single, bounded event.
* '''Imperfective''' aspect focuses on the internal structure of an action, viewing it as ongoing, habitual, or incomplete. The imperfective can describe actions that were happening in the past, are happening in the present, or will be happening in the future, without specifying an endpoint.
** '''Progressive''' aspect is a subtype of the imperfective; it specifically indicates actions that are <u>ongoing at the reference time</u>. It zooms in on the process of the action.
** '''Habitual''' aspect is another subtype of the imperfective; it describes actions that occur <u>regularly or habitually over a period of time</u>.
* '''Perfect''' aspect focuses on the <u>outcome or result</u> of an action rather than the action itself. It implies that the action, which occurred in the past, has relevance or consequences for the present or future.

* '''Prospective''' aspect indicates that an action is about to happen, focusing on the period immediately before the action starts.
* '''Iterative or Frequentative''' aspect describes actions that are repeated multiple times.
* '''Stative''' aspect refers to states or conditions rather than actions, emphasizing the static nature of the verb's meaning.

Some languages (especially in the <u>Slavic</u> subfamily) have pairs of verbs that differ only in aspect, known as '''aspectual pairs'''. They consist of one verb with a <u>perfective aspect</u> and another with an <u>imperfective aspect</u>, each capturing different '''temporal contours''' of the same action.

The <u>Russian</u> verb "писать/нап-исать" (to write) demonstrates how aspectual pairs work:

# <u>Imperfective Aspect</u>: "писать" (pisat')
#* This form is used to indicate an ongoing action, a repeated action, or a general statement about the action without specifying its completion.
#* "Она пишет письмо" (Ona pisat' pis'mo) — "She writes a letter" or "She is writing a letter." Here, the action is not necessarily completed; it might be ongoing or habitual. This aspect captures the process or internal duration of the action, without indicating whether the action has been completed; it's about the action in progress or habitually done over time.
# <u>Perfective Aspect</u>: "написать" (napisat')
#* This form denotes the action's completion, focusing on the outcome rather than the process.
#* "Она написала письмо" (Ona napisala pis'mo) — "She has written a letter." The focus is on the fact that the letter has been completed. This aspect views the action as a finished whole, emphasizing the action's completed state and its results.

This distinction between perfective and imperfective aspects can intersect with tense to provide a nuanced temporal framework; in <u>Russian</u>, tense is primarily marked on the imperfective verb, while the perfective verb inherently carries a sense of completion.

Aspect can be expressed through various means depending on the language; many languages use '''affixes''' or '''verb conjugation''' to indicate aspect (morphology). In <u>periphrastic</u> languages, aspect can be indicated by '''auxiliary verbs''' or '''verb phrases''', while some languages known for '''suppletion''' use <u>entirely different verbs</u> to express aspectual distinctions.

'''Periphrasis''' uses a combination of auxiliary verbs alongside the main verb, rather than through inflection or single aspectual verbs; it allows more than one word to convey the temporal structure, phase, or continuity of the action or state described by the verb. 

The use of auxiliary (or '''helping''') verbs in combination with the main verb is central to periphrastic aspect expression; these auxiliaries modify the main verb to indicate aspectual nuances such as <u>ongoing action</u>, <u>completion</u>, or <u>repetition</u>. Unlike with inflectional strategies, the main verb often remains in a base or '''infinitive form''', and aspectual distinctions are made through the auxiliary verbs and their placement. 

Because this form of aspect expression relies on '''syntax''' (the arrangement of words) rather than '''morphology''' (word structure changes), it allows for considerable flexibility in how actions and states can be temporally framed within a sentence. 

* "She is singing;" the auxiliary verb "is" combined with the present participle "singing" expresses an ongoing action. 
* "She has sung;" the auxiliary "has" combined with the past participle "sung" indicates a completed action with relevance to the present. 
* "Elle va chanter;" (she is going to sing). The verb "va" (goes) combined with the infinitive "chanter" (to sing) expresses an action that is about to happen in the near future.

Languages that rely heavily on periphrastic constructions for aspect expression tend to be more '''analytic'''; synthetic languages tend to encode aspect directly onto the verb through inflection. Periphrastic constructions can offer a wide range of nuanced temporal distinctions, reflecting subtle differences in how an action is viewed in terms of its progress, completion, or frequency. Over time, periphrastic constructions can become '''grammaticalized''' into more condensed forms, showing how languages can evolve from more analytic to more synthetic expressions, or vice versa.

'''Suppletion''' occurs when a language uses entirely different roots to express grammatical variations such as tense, number, person, or, as in this case, aspect, which results in pairs or sets of words that are related in meaning but have no resemblance in form.

In the context of aspect, suppletive forms are used to differentiate between how an action or state is viewed in terms of its temporal flow - such as whether it is ongoing, completed, or habitual. Suppletion in aspect is less common than in tense or person marking but can be found in languages that have a high degree of irregularity or in verbs that are frequently used and thus subject to historical changes and irregularities.

A compelling example of using completely different roots to signify aspectual differences comes from <u>Irish</u> (<u>Gaelic</u>); Irish, like other <u>Celtic</u> languages, often exhibits suppletion in its verb system. The verb "to be" in Irish has the root "bí" for the present tense, which is used in contexts that suggest habitual or ongoing actions. "Bíonn siad ag siúl" – "They walk (habitually)" or "They are walking (as a general activity)." For the past tense, indicating completed actions, <u>Irish</u> uses a completely different root, "bhí." "Bhí siad ag siúl" – "They walked" or "They were walking (at a specific instance in the past)."

=== Mood ===
Conveys the speaker's '''attitude''' towards the action or state described by the verb, indicating '''modality''' - the manner in which the action is regarded or related to reality. Unlike tense, which places actions or states in time, and aspect, which describes the nature of the action's flow, mood deals with the speaker's perspective on the <u>certainty</u>, <u>necessity</u>, or <u>desirability</u> of the event, among other nuances.

* The '''indicative mood''' is the most common, used for stating facts or asking questions. It presents the action or state as <u>real</u>, <u>actual</u>, or <u>certain</u>. "She goes to school" (a statement of fact).
* The '''imperative mood''' is used for commands, requests, or prohibitions; it directly addresses the listener and expresses a '''directive'''. "Go to school!" (a command).
* The '''subjunctive mood''' is used to express wishes, hypothetical situations, demands, or conditions contrary to fact. It often indicates something <u>desired</u>, <u>possible</u>, or <u>imagined</u>. "If she were president, she would change the law" (a hypothetical situation).
* The '''conditional mood''' indicates actions or states that are dependent on certain conditions. It often expresses <u>hypothetical</u> outcomes and is sometimes considered a subcategory of the subjunctive. "She would go to school if she woke up early" (a condition and its potential outcome).
* The '''optative mood''' is found in some languages, expressing <u>wishes</u> or <u>hopes</u>. "May you have a long life!" (a wish).
* The '''jussive mood''' is used to express <u>commands</u>, <u>suggestions</u>, or <u>necessity</u>, often in the first or <u>third person</u>. "Let us pray" (a suggestion or command).

* The '''potential mood''' expresses <u>possibility</u> or <u>capability</u>. "She might go to school" (a possibility).

* The '''interrogative mood''' is recognized by some linguists, used for asking questions. "Does she go to school?" (a question).

Mood is closely related to modality, which more broadly refers to the speaker's attitude regarding the likelihood, necessity, or obligation of the action or state. Modality can be expressed through mood, but also through '''modal verbs''' ("can," "must," "should"), adverbs, or other linguistic means, depending on the language.

The expression and classification of mood can vary significantly across languages. Some languages have distinct morphological markers for mood, with specific verb forms for the subjunctive, conditional, or imperative moods. In other languages, mood may be indicated more subtly through context, word order, particles, or the use of modal auxiliary verbs without distinct morphological changes to the main verb. While the moods listed above are relatively common, individual languages may have additional moods or lack some of these categories altogether. 

== Voice and Valency ==

=== Voice ===
Describes the relationship between the action expressed by the verb and the participants identified by the subject, object, and sometimes other parts of the sentence. It's a way to articulate <u>who is doing</u> the action and <u>who is receiving</u> it, highlighting different aspects of the event or state described by the verb. Voice can change the focus of a sentence without altering the factual content of the action being described.

In the '''active''' voice, the subject of the sentence <u>performs the action</u> of the verb. The focus is on the '''agent''' (the doer) of the action; active voice constructions are '''direct''' and are often used to emphasize the agent's role in the action. 

In the '''passive''' voice, the focus shifts from the agent to the '''recipient''' (or '''patient''') of the action. The subject of the sentence is the entity that <u>experiences the action</u>, while the doer of the action (if mentioned) comes later in the sentence.

In the '''middle''' voice found in some languages, the subject performs an action <u>upon themselves</u> or <u>for their benefit</u>. It blurs the distinction between the '''agent''' and '''patient''' roles. In <u>Ancient Greek</u>, the middle voice could be used for reflexive actions or situations where the subject acts in its own interests.

Languages may have additional voices that provide different perspectives on the action. 

* '''Causative''' voice indicates that the subject causes someone else to perform the action.
* '''Reflexive''' voice shows that the subject performs the action upon themselves.
* '''Reciprocal''' voice is used when subjects perform the action on each other.
* '''Antipassive''' voice is found in '''ergative-absolutive''' languages; it decreases the '''valency''' of transitive verbs, often omitting or demoting the object, and focusing on the action and its '''agent'''.

=== Valency ===
Refers to the '''capacity''' of verbs to combine with a specific number of arguments (subjects, objects, or complements) to form a complete and meaningful sentence. It is a concept that helps in understanding how verbs function and interact with other sentence elements to convey information. The term originates from chemistry, where it describes how atoms combine based on their number of valence electrons, similarly applied in linguistics to describe how verbs "bond" with their arguments.

<u>Intransitive verbs</u> ('''monovalent''') require only <u>one argument</u> (typically a '''subject''') to form a complete sentence. They do not take a '''direct object'''. "The baby slept."

<u>Transitive verbs</u> ('''divalent''') need <u>two arguments</u> to complete their meaning - a '''subject''' that <u>performs</u> the action and a '''direct object''' that <u>receives</u> the action. "She reads a book."

<u>Ditransitive verbs</u> ('''trivalent)''' require <u>three arguments</u>: a '''subject''' who <u>performs</u> the action, a '''direct object''' that <u>receives</u> the action, and an '''indirect object''' that <u>is affected</u> by the action. "He gave her a gift."

Processes like '''passivization''' (the transformation from active to passive voice) can reduce a verb's valency by removing the need for an explicit subject, as in the transformation from "She opens the door" to "The door is opened." Conversely, certain constructions can increase a verb's valency by adding arguments, such as '''causatives''' which make an intransitive verb take an additional '''causee''' argument: "He made her laugh." Some linguists also talk about '''zero-valent''' verbs (or '''weather verbs''') that do not require any arguments, expressing <u>situations</u> rather than <u>actions</u> performed by agents: "It is raining."

Valency is crucial for sentence structure, influencing word order and the use of grammatical markers such as prepositions or case markings to identify the roles of different arguments. Understanding valency helps in identifying the semantic roles played by different sentence elements, like agent, patient, theme, or experiencer, enhancing the analysis of sentence meaning. Valency patterns vary significantly across languages, with some languages offering more flexibility in valency alteration than others. This variability is a key area of study in typological linguistics and comparative grammar.

'''Applicatives''' allow for the addition of an argument to a verb that wouldn't normally take it, effectively increasing the valency of the verb. This is achieved by applying an applicative morpheme to the verb, which enables the inclusion of an indirect object, beneficiary, location, instrument, or other roles directly into the verb phrase. Unlike causatives, which introduce a causee and create a causation relationship in the action, applicatives enhance the verb to involve an additional participant more directly in the action or event described.

Applicatives increase a verb's valency by adding a new argument to the core argument structure of the verb; this additional argument is often an '''indirect object''' but can also express other semantic roles. The added argument can specify a wide range of roles, including but not limited to:

* <u>Beneficiary</u>: Who benefits from the action.
* <u>Location</u>: Where the action takes place.
* <u>Instrument</u>: What is used to perform the action.
* <u>Reason</u>: Why the action is performed.

In languages with applicative constructions, the addition of an applicative morpheme to the verb signals that an extra argument is being integrated into the verb's argument structure. This morpheme can be a prefix, suffix, or infix, depending on the language's morphological typology.

In <u>Chichewa</u> (a <u>Bantu</u> language), the applicative suffix "-ir-" can be added to a verb to include an indirect object or beneficiary. For instance, from "pita" (go) to "pitira" (go for the sake of), allowing the sentence to include whom the action is performed for. In <u>Navajo</u> (a Na-Dené language), the use of certain verbal prefixes can add locative or instrumental arguments to the action described by the verb, altering its valency to directly incorporate these elements into the action's core meaning.

Applicatives provide a mechanism for languages to manipulate and expand syntactic possibilities, allowing speakers to incorporate additional information directly into the verb phrase and providing a flexibility to verbal valency. By incorporating additional participants directly into the verb's argument structure, applicatives can offer a more nuanced and precise way to express actions and relationships between entities. 

== Research Frameworks in Comparative Linguistics ==

=== Typological Linguistics ===
Typological linguistics is concerned with the systematic study and classification of languages based on their '''structural features''' and '''functional properties''', <u>irrespective of their historical relationships</u>. It aims to identify patterns of similarity and diversity across languages, seeking to understand the range of possible linguistic structures and how these structures are used to convey meaning.

The focus is on cross-linguistic comparison to categorize languages into types based on shared grammatical, phonological, or syntactic characteristics. For example, languages might be compared based on their word order (SOV, SVO, VSO, etc.), morphological typology (analytic, synthetic, agglutinative, polysynthetic), or systems of tense, aspect, and mood. 

Typological linguistics aims to uncover '''universal principles''' of language, '''constraints''' on linguistic variation, and potential pathways of '''language change'''. It helps linguists understand not only how languages differ but also how they are similar and what limits there might be on linguistic structure.

This approach uses a broad sample of languages, often from unrelated language families, to identify patterns and constructs typologies that can account for the structural diversity observed.

=== Areal Linguistics ===
Areal linguistics, or linguistic area studies, examines how languages <u>within a specific geographical region influence one another</u> through prolonged contact, leading to '''shared linguistic features''' across language families or branches. This field is particularly interested in the phenomenon of '''language convergence''' and the formation of linguistic areas or sprachbunds.

A '''sprachbund''' is a group of languages that, although they may belong to different language families, have come to share certain features because of geographical proximity and prolonged language contact. The concept highlights the importance of interaction between speaking communities in the development of linguistic features, rather than shared <u>genetic heritage</u>. Languages within a sprachbund influence each other through '''borrowing''' and '''convergence''', leading to similarities in grammar, syntax, vocabulary, phonology, and pragmatics that are not due to a common ancestral language.

The languages involved in a sprachbund are spoken in a geographically continuous area. There is a significant overlap in structural or lexical features across the languages, which cannot be attributed to common ancestry. The shared features often cut across language families, indicating that borrowing and convergence, rather than inheritance, are the sources of similarity. Typically, there is a history of multilingualism or extensive bilingualism among the speakers of the languages in the area, facilitating the transfer of linguistic features.

One of the most cited examples of a sprachbund is the <u>Balkans</u>, which includes languages from different families, such as <u>Slavic</u> (<u>Bulgarian</u>, <u>Macedonian</u>), <u>Romance</u> (<u>Romanian</u>), <u>Albanian</u>, and <u>Greek</u>. Despite their diverse genealogical origins, these languages share several features, including:

* Postposed definite articles (the definite article appears after the noun).
* A similar structure for expressing the future tense.
* Use of the same or similar mood systems, including a subjunctive or optative mood.
* Loss of the infinitive, replaced by subjunctive or other constructions.

The concept of a '''language continuum''' refers to a situation where adjacent dialects are '''mutually intelligible''', but as one moves geographically across the continuum, mutual intelligibility decreases, and the dialects at the extremes may not understand each other at all. This often occurs in extensive geographical areas where no sharp boundaries exist between the dialects or languages. The <u>North Germanic</u> languages (<u>Scandinavian</u> languages) are sometimes considered to form a continuum. 

While both of these conceptual frameworks emphasize the fluidity of language boundaries and the importance of interaction between languages, they differ in focus. A sprachbund focuses on the convergence of features across language families due to contact, whereas a language continuum deals with gradations of mutual intelligibility within a closely related group of dialects or languages, often within a single language family.

In areal linguistics, the emphasis is specifically on <u>geographic proximity</u> and <u>language contact</u> as the primary factors driving similarities among languages in a given area. Areal features can include phonetic, lexical, syntactic, and morphological traits that have spread among neighboring languages. 

By concentrating on geographical regions and the linguistic borrowing and convergence within them, areal linguistics captures a "snapshot" of linguistic features shared across language boundaries due to historical contact. This approach highlights the fluidity of language change and the significant role of sociolinguistic factors in shaping linguistic landscapes.

Typological linguistics conversely seeks to identify patterns and categories of linguistic structure that emerge across languages, potentially integrating the insights from areal linguistics into a broader framework. This can involve observing how areal features might lead to typological tendencies or "universals" that transcend individual language families and regions, reflecting deeper cognitive or functional principles governing language structure and change.

Typological linguistics can be viewed as applying the insights gained from areal linguistics across the temporal spectrum, tracing how '''contact-induced changes''' can become entrenched in languages over time and contribute to the emergence of cross-linguistic patterns. This approach underscores the importance of historical linguistics in understanding the evolution of typological features, as it provides the temporal depth necessary to observe how transient areal features might stabilize into enduring typological traits.
[[Category:Linguistics]]