This text describes the grammar of Old Turkic, the earliest directly attested Turkic language, documented in 7th to 10th-century inscriptions in the "runic" script in Mongolia and the Yenisey basin, 9th to 13th-century Uygur manuscripts from Chinese Turkestan in Uygur, runic and other scripts (comprising religious, legal, literary, medical, folkloric, astrological and personal material) and 11th-century Qarakhanid texts, mostly in Arabic writing. All aspects of the language are dealt with: phonology; subphonemic phenomena and morphophonology and the way these are reflected in the various scripts; derivational and inflectional morphology; grammatical categories; word class; syntax; lexical fields; discourse types; and phraseology as well as stylistic, dialect and diachronic variation.