Indo-European Languages

The Indo-European language family, one of the world's largest language families, encompasses a wide range of languages spoken across Europe, Asia; through much of the world by way of European colonization. Despite the significant diversity in the family, resulting from thousands of years of evolution, migration, and contact with unrelated languages, there are common traits that can be traced back to their shared ancestry. These commonalities, while sometimes abstract or obscured by language change, include phonological, morphological, syntactic, and lexical features.

Common Traits

Indo-European languages split into two groups based on their treatment of certain velar consonants. Centum languages (like Latin, Greek, and Germanic languages) merged or kept these velars distinct, while Satem languages (like Indo-Iranian languages) palatalized them.

Certain phonological changes, such as Grimm's Law in Germanic languages (a systematic shift of consonant sounds) can be traced back to common Indo-European roots.

Many Indo-European languages utilize inflections to convey grammatical relationships. This includes the use of case endings in nouns to indicate their role in a sentence (nominative, accusative, genitive) and verb conjugations to express tense, mood, aspect, and voice. A common trait is the distinction between aspect (perfective versus imperfective) and mood (indicative, subjunctive, imperative) in verb systems, although the specifics can vary widely among the languages.

It is hypothesized that the Proto-Indo-European language might have predominantly used an SOV (Subject Object Verb) word order, which is still found in some modern Indo-European languages, although many have shifted to SVO (Subject Verb Object).

There are many cognates (words derived from a common ancestral word) across Indo-European languages in basic vocabulary such as family terms (mother, father), numbers, and body parts. The reconstruction of the Proto-Indo-European language has provided a basis for identifying these common roots. Similar processes for creating words from roots, including suffixation and prefixation, can be observed across the family.

Comparative mythology has found recurring themes and deities in the mythologies of various Indo-European cultures, suggesting a common proto-mythology. Similarities in poetic and metrical forms have been observed, indicating a shared tradition of oral literature.

It's important to note that while these traits can be identified across Indo-European languages, the extent and manner in which they are present can vary greatly due to the vast time scale of linguistic evolution, geographical dispersion, and contact with non-Indo-European languages. Additionally, the Indo-European family is a historical construct based on linguistic evidence; thus, the features of individual languages have diverged significantly from their proto-language over millennia.

Indo-European Language Branches

The family consists of several major subfamilies:

• Anatolian, an extinct branch of languages spoken in/around Anatolia, in modern Türkiye.
• Balto-Slavic, spoken across Central Europe and Eastern Europe.
• Celtic, spoken across France, Belgium, Ireland, the British Isles, Iberia, and beyond.
• Germanic, initially spoken in Northern Europe and Scandinavia.
• Hellenic (including Ancient Greek), spoken around the Aegean, Mediterranean, and Black Sea.
• Indo-Iranian, initially spoken around the Iranian plateau and then into Central Asia and South Asia.
• Italic (including Latin), spoken by the peoples of the Italian peninsula.

There are also a number of languages that are within the Indo-European family but do not necessarily belong to a distinct branch of subfamily:

• Albanian
• Armenian
• Tocharian
• Thracian
• Illyrian
• Dacian
• Liburnian
• Ligurian
• Lusitanian
• Messapic
• Phrygian

Proto-Indo-European Roots

The Proto-Indo-European (PIE) language is the hypothetical common ancestor of the Indo-European language family. Despite the absence of direct records, linguists have reconstructed aspects of PIE based on systematic comparisons of its descendant languages, utilizing the comparative method. This reconstruction offers insights into its phonology, morphology, syntax, and lexicon, as well as aspects of the culture and environment of its speakers. The consensus on PIE, while robust in many areas, is still subject to ongoing research and debate.

PIE is believed to have had a complex system of consonants and vowels, with distinctions between voiced, voiceless, and aspirated stops, as well as sonorants (nasals, liquids) and sibilants. The existence of laryngeal sounds, which have left their trace primarily in the vowel system of descendant languages, is a significant aspect of PIE phonology that was uncovered through the analysis of anomalies in the phonetic patterns of these languages.

Most scholars now believe there were three distinct laryngeals, which can be written H₁, H₂, and H₃. Of these, H₁ may have been h or a glottal stop; H₂ was perhaps a pharyngeal spirant like Arabic ḥ in ḥams ‘five’; H₃, whatever its other features, was probably voiced. When laryngeals between consonants disappeared a vowel sometimes remained, as in Greek stásis, Sanskrit sthitis, Old English stede ‘a standing (place)’ from Proto-Indo-European *stH₂tis. Before the advent of the laryngeal theory, a separate Proto-Indo-European vowel ə (called schwa indogermanicum) was reconstructed to account for these correspondences.

PIE nouns and adjectives are reconstructed with a system of declensions, including cases such as nominative, accusative, genitive, dative, and ablative; gender (masculine, feminine, and neuter) and number (singular, dual, and plural) distinctions were also present. The PIE verb system is believed to have included aspects (imperfect versus perfect), mood (indicative, subjunctive, optative, imperative), voice (active, middle, and possibly passive), and a rich set of conjugations to express tense (present, past, future).

The reconstructed syntax of PIE suggests a flexible word order with a tendency towards SOV (Subject-Object-Verb), similar to many of its ancient descendants such as Sanskrit and Ancient Greek. The use of cases allowed for this flexibility, as syntactic roles were marked on the nouns rather than determined by position.

Reconstruction of the PIE lexicon has provided insights into the culture and environment of its speakers. Terms related to family, animals, nature, agriculture, technology, and the divine suggest a pastoral-agrarian society. Thus is it supposed that the community knew and talked about dogs (*ḱwón-), horses (*H₁éḱwo-), sheep (*H₃éwi-), and almost certainly cows (*g^wów-) and pigs (*súH-), all of which were likely domesticated.

At least one cereal grain was known (*yéwo-), and at least one metal (*H₂éyos). There were vehicles (*wóǵho-) with wheels (*k^wék^wlo-), pulled by teams joined by yokes (*yugó-). Honey was known, and it probably formed the basis of an alcoholic drink (*mélit-, *médhu) related to the English mead. Numerals up through 100 (*ḱm̥tóm) were in use. All this suggests a people with a well-developed Neolithic or even Chalcolithic technology.

While more speculative, the reconstruction of PIE vocabulary has led scholars to infer aspects of PIE society, including its patrilineal and patriarchal structure, importance of kinship and hospitality, and practices related to agriculture, animal husbandry, and warfare. Mythological reconstructions point towards a religion that included sky father gods, earth mother goddesses, and a complex set of ritual practices.

Divergence of PIE into the IE Language Family

It is difficult, if not impossible, for linguists to date the divergence from PIE based on the existing evidence. The best that can be done is to estimate how different each language is to the others, and then comparing that degree of difference across the family (paying special attention to branches like the Romance subfamily, where dates of divergence have a stronger foundation).

Based on this, it is generally 'calculated' that the earliest branches of Indo-European languages (Anatolian, Indo-Iranian, and Hellenic) began to emerge ~3000 BCE, with the ancestral (PIE) language itself likely emerging up to a millennium before this. The initial PIE population was likely a small, homogenous Eurasian group that expanded and fragmented significantly around ~4000 BCE.

Some scholars associate this group with the Kurgan (Barrow) culture of the Black Sea, Caucasus, and regions west of the Ural Mountains, but it was only one of many steppe cultures that extended across the entire Black Sea to Caspian Sea region (the Caucasus; modern Russia; Georgia; Azerbaijan; Armenia; and NE Türkiye. It is more reasonable to assume that PIE people came from the region, without identifying a specific cultural antecedent.

• Ciscaucasia lies within Russian territory and includes the foothills and plains extending northward from the primary range of the Caucasus Mountains. It is home to the North Caucasus Federal District, which encompasses several Russian republics.
• Transcaucasia is south of the Caucasus Mountains and includes the modern countries of Georgia, Armenia, and Azerbaijan.

A remote relationship of Indo-European to the Uralic languages is possible; both families appear to have developed in relatively close proximity, and they share a number of similarities in terms of grammatical elements (particularly with pronouns, personal endings of verbs, the accusative case, and some terms). Both families also have many suffixes but few or no prefixes or infixes. Aside from these features, there are few other similarities - so if they are related, it would have been through an ancestor that existed thousands of years ago. Still, there are many more similarities between Indo-European and Uralic as compared to other language families such as Afro-Asiatic and Kartvelian, indicating a closer temporal proximity in terms of when they diverged from one another. The idea of any kind of reconstructed superfamily preceding them is bereft of evidence.

As PIE split into the dialects that would eventually spawn the family's first daughter languages, different regions developed distinct changes. Among the Central Asian and Eastern European dialects, the palatal stops (*ḱ, *ǵ, and *ǵh) favored by PIE were changed into fricatives (s, ś, th, et cetera) or affricates (ch, j). In this way, from the basic PIE element *H₂eḱ (meaning ‘sharp, pointed') we see the following transmutations:

• Sanskrit: aśri - 'edge.’ The change from PIE *ḱ to "ś" is characteristic.
• Old Church Slavonic: ostrŭ - ‘sharp.' Reflecting the common Slavic treatment of PIE *ḱ as 's' or 'st.'
• Armenian: asełn - ‘needle.'
• Albanian: athëtë - ‘bitter.’
• Greek: ákros meaning ‘tip.’ The change from *ḱ to 'k' is a feature of Greek phonology.
• Latin: acidus meaning ‘biting,' *ḱ becoming 'c' is a common Latin development.

Satem versus Centum

The languages that change the palatal stops into affricates are known as the satem languages - from the Avestan word satəm ‘hundred’ (from PIE *kmtóm), which illustrates the change. The languages that preserve the palatal stops as k-like sounds are known as centum languages, from centum (/kentum/), the corresponding word in Latin. Satem languages are not geographically separated from one another by any centum languages, which implies this change happened only once, but occurred across a contiguous language area of PIE.

Boundaries between Satem and Centum Languages

Generally, there is an east-west division within the family, with the satem languages predominantly situated in the east, and the centum languages occupying the west.

The boundary begins in Europe, where the Baltic and Slavic languages mark the westernmost extent of the satem languages. The division here separates the satem-speaking Slavic and Baltic regions from the centum-speaking Germanic and Romance-speaking areas of Western Europe.

The boundary continues, separating the Slavic languages in Eastern Europe from the Germanic languages to the northwest and the Romance languages to the southwest. The Satem-Centum divide here is not purely geographical but correlates with the linguistic landscape shaped by historical migrations and the Roman Empire's influence.

The boundary extends south, where the historical presence of satem-speaking Thracian, Dacian, and Illyrian languages differentiated these areas from the centum-speaking regions of ancient Italy and Greece. This area is more complex due to the historical movements of peoples and the eventual dominance of Slavic languages in much of the Balkans. To the northeast of the Black Sea, the boundary delineates the Indo-Iranian languages of the satem group from the Anatolian languages and the ancient Greek dialects, which were centum languages.

The boundary extends into Asia, encompassing the vast area of Iran and Central Asia, where Iranian languages are spoken, and further into South Asia, home to the Indo-Aryan languages. The boundary skirts around the Caucasus region, which is linguistically diverse and includes languages from both the Indo-European family (including Armenian, a satem language) and many non-Indo-European languages.