Turkic languages

The Turkic languages form a family of over 35 documented languages, spoken by Turkic peoples across a vast stretch of Eurasia—from Southeastern and Eastern Europe through Central Asia, West Asia, East Asia, and into North Asia (Siberia). Their origins lie in a region of East Asia spanning Mongolia to Northwest China, where the ancestral Proto-Turkic language is believed to have been spoken. From there, these languages spread into Central Asia and further westward during the first millennium CE, forming a dialect continuum.

Approximately 200 million people speak Turkic languages today. The most widely spoken is Turkish, primarily in Anatolia and the Balkans, accounting for about 38% of all Turkic speakers, followed by Uzbek. Nearly all Turkic languages share common features: vowel harmony, agglutination, subject-object-verb word order, and a lack of grammatical gender. Within the family, mutual intelligibility is high among the Oghuz subgroup—which includes Turkish, Azerbaijani, Turkmen, Qashqai, Chaharmahali Turkic, Gagauz, and Balkan Gagauz, as well as Oghuz-influenced Crimean Tatar—after moderate exposure. Other subgroups also show varying degrees of mutual intelligibility. Classification typically divides the family into two branches: Oghur, whose only surviving language is Chuvash, and Common Turkic, which encompasses all others.

Turkic languages share notable similarities with Mongolic, Tungusic, Koreanic, and Japonic languages. These parallels led some linguists, such as Turkologist Talât Tekin, to propose an Altaic language family, though this idea is widely rejected by historical linguists. Similarities with Uralic languages once prompted the Ural-Altaic hypothesis, but insufficient evidence exists to confirm either macrofamily. Current scholarship attributes the shared traits to extensive prehistoric language contact. On 15 December 1893, the Orkhon Inscriptions—among the earliest Turkic texts—were deciphered; UNESCO later declared that date as "World Turkic Language Family Day."

Turkic languages are null-subject languages, featuring vowel harmony (with Uzbek a notable exception due to strong Persian-Tajik influence), converbs, extensive agglutination through suffixes and postpositions, and no grammatical articles, noun classes, or gender. Subject-object-verb order is universal. Tuvan exhibits nearly full vowel harmony, while Uzbek shows the least or none. The family’s documented history, spanning over a millennium from inscriptions and texts, reveals a clear trajectory in the evolution of vowel harmony. Although vowel harmony is common across Inner Eurasian families (Mongolic, Tungusic, Uralic, and Turkic), the type differs: Uralic and Turkic share palatal vowel harmony, whereas Mongolic and Tungusic represent a distinct type.

The prehistoric homeland of Turkic peoples and their language is thought to lie between the Transcaspian steppe and Northeastern Asia (Manchuria), with genetic evidence pointing to South Siberia and Mongolia as the "Inner Asian Homeland." Linguists such as Juha Janhunen, Roger Blench, and Matthew Spriggs suggest modern-day Mongolia as the Proto-Turkic homeland. Turkologist Peter Benjamin Golden, based on Proto-Turkic words for climate, topography, flora, fauna, and subsistence, places the Urheimat either in the southern taiga-steppe zone of the Sayan-Altay region or from Lake Baikal to eastern Mongolia. Extensive contact between Proto-Turks and Proto-Mongols occurred around the first millennium BC, giving rise to a shared "Turco-Mongol" cultural tradition, including the religion Tengrism. Loanwords flowed both ways, but Turkic borrowings now form the largest foreign component in Mongolian vocabulary. More recent scholarship attributes lexical and typological similarities among Turkic, Tungusic, Mongolic, Korean, and Japonic to prehistoric contact within a Northeast Asian sprachbund. A later (circa first millennium BC) contact among "core Altaic" languages (Turkic, Mongolic, Tungusic) is distinguished by a pattern: Turkic words were mostly borrowed into Mongolic, then from Mongolic into Tungusic; Turkic borrowings into Mongolic far outnumber the reverse, and Turkic and Tungusic share no words not also found in Mongolic. Turkic languages also contain Chinese loanwords from early Proto-Turkic times.

The earliest written records of Turkic languages are the Orkhon inscriptions, created by the Göktürks in Old Turkic, discovered in 1889 in Mongolia’s Orkhon Valley, and dated accordingly.