The Uyghur or Uighur language (// ئۇيغۇر تىلى, Уйғур тили, Uyghur tili, Uyƣur tili or ئۇيغۇرچە, Уйғурчә, Uyghurche, Uyƣurqə), formerly known as Eastern Turki, is a Turkic language with 10 to 25 million speakers, spoken primarily by the Uyghur people in the Xinjiang Uyghur Autonomous Region of Western China. Significant communities of Uyghur-speakers are located in Kazakhstan and Uzbekistan, and various other countries have Uyghur-speaking expatriate communities. Uyghur is an official language of the Xinjiang Uyghur Autonomous Region, and is widely used in both social and official spheres, as well as in print, radio, and television, and is used as a common language by other ethnic minorities in Xinjiang.
Uyghur belongs to the Karluk branch of the Turkic language family, which also includes languages such as Uzbek. Like many other Turkic languages, Uyghur displays vowel harmony and agglutination, lacks noun classes or grammatical gender, and is a left-branching language with subject–object–verb word order. More distinctly Uyghur processes include, especially in northern dialects, vowel reduction and umlauting. In addition to influence of other Turkic languages, Uyghur has historically been influenced strongly by Persian and Arabic, and more recently by Mandarin Chinese and Russian.
The modified Arabic-derived writing system is the most common and the only standard in China, although other writing systems are used for auxiliary and historical purposes. Unlike most Arabic-derived scripts, the Uyghur Arabic alphabet has mandatory marking of all vowels due to modifications to the original Perso-Arabic script made in the 20th century. Two Latin and one Cyrillic alphabet are also used, though to a much lesser extent. The Arabic and Latin alphabets both have 32 characters.
Kagan Arik wrote that Modern Uyghur is not descended from Old Uyghur, rather, it is a descendant of the Karluk language spoken by the Kara-Khanid Khanate. According to Gerard Clauson, Western Yugur is considered to be the true descendant of Old Uyghur, and is also called "Neo-Uyghur". Modern Uyghur is not a descendant of Old Uyghur, but is descended from the Xākānī language described by Mahmud al-Kashgari in Dīwānu l-Luġat al-Turk. According to Frederik Coene, Modern Uyghur and Western Yugur belong to entirely different branches of the Turkic language family, respectively the southeastern Turkic languages and the northeastern Turkic languages. The Western Yugur language, although in geographic proximity, is more closely related to the Siberian Turkic languages in Siberia. Robert Dankoff wrote that the Turkic language spoken in Kashgar and used in Kara Khanid works was Karluk, not (Old) Uyghur.