ProtoTurkic

Proto-Turkic is the reconstructed common ancestor of the Turkic languages, a hypothetical language used by historical linguists to explain shared innovations and correspondences across distinct Turkic languages. Because there are no contemporary records of Proto-Turkic, its features are inferred through the comparative method from attested Turkic languages, including Old Turkic and later branches.

Most scholars place its homeland in the Eurasian steppe, with the plausible locus in the Altai-Sayan region of southern Siberia and adjacent steppes. The temporal frame is the first millennium BCE to the early centuries CE, lying before the earliest documentary Turkic texts of the 8th century CE.

Proto-Turkic is reconstructed as an agglutinative, suffixing language with vowel harmony, a predominantly SOV word order, and a rich system of grammatical cases. The phonology is not fully settled, but reconstructions point to a consonant inventory and vowel system that produced characteristic Turkic developments, including vowel harmony that permeates suffixation.

The language gives rise to the major Turkic lineages, notably split into the Oghur branch (including Chuvash) and the Common Turkic branch, from which most modern Turkic languages descend (Oghuz, Kipchak, Karluk, Siberian Turkic, etc.). Old Turkic, first attested in inscriptions of the 8th century CE, preserves features inherited from Proto-Turkic, but Proto-Turkic itself remains a theoretical construct essential for understanding Turkic history and linguistic phonology.