Abstract
In the history of the Turkic languages, such converbal suffixes as -a, -e and -u, -ü appear in almost all written literary languages, starting from the early Orkhon inscriptions and continuing to the later Karakhanid, Khwarezmian, and Chagatai texts. It is difficult to say that the converbs -a, -e were actively used in the Mamluk-Kipchak monuments. However, they can occur in the same form in six different contexts. We observe that in a sentence containing an action expressed by additional information, the main role belongs to the action itself, whereas the additional information plays a more passive role. The suffixes -u and -ü in the history of the Turkic language did not act as active suffixes in a number of cases. In many instances, the suffixes -a, -e remained unnoticed. Even after the 14th–15th centuries, their usage gradually ceased. In earlier periods, constructions with the suffixes -a , -e were common, but in later periods, they were limited to the forms -yu and -yü , characteristic of verbs ending in vowels. Over time, the suffixes u and ü , underwent elision, and their meaning merged into the sound y . Some researchers considered the suffixes -a , -e and - u, -ü as separate suffixes: some regarded them as synonyms, while others treated them as phonetic variants of a single suffix. The study revealed that they represent dialectal parallel forms. Thus, the suffixes - u, -ü and -a, -e can be considered dialectal parallels.