Throughout the history of Turkic, the future tense affix exhibits different forms and frequently changes over time. In the modern Turkish of Turkey, the future tense suffix –acak/-ecek corresponds to several different affixes used in the Old Turkic period. In this article, the future tense suffixes used in Orkhon and Uyghur Turkic are examined, and their functions, roots, and the personal suffixes used in their conjugations are discussed. After providing a brief overview of the Göktürks, the Orkhon Inscriptions, and Orkhon Turkic in the introduction, the main concern of this article, the future tense, is introduced. Future tense verb conjugations found in the Orkhon ınscriptions, in which personal pronouns and possessive suffixes are used, are presented in tables showing how they are formed for all persons, singular and plural. After discussing the etymology of the future tense affix –DaçI, its conjugation, again showing all singular and plural persons, is presented in table format. Discussion of the future tense affixes –sIk and –çI is followed by examples found in the texts. Next, examples of the unrealized future tense are given, after which general information regarding the period of Uyghur Turkic is presented. The etymologies and conjugations of the future tense suffixes -ga and -GAy are discussed, followed by relevant examples. Future tense affixes and conjugations in Uyghur Turkic are examined in this study with the goal of contributing to future research on these topics.

Key words: Orkhon Inscriptions, Uyghur Turkic, future tense, Old Turkic, tense affixes.