Goals. The study compares the suffix {+cAn} used as a noun derivational suffix in most Turkic languages — and the suffix {-cAn} which forms participles and is used as a verb conjugation suffix in the Khakas and Shor languages, with an emphasis on the relationship of these suffixes to the suffix {-(V)wcAn} which is used as a verb conjugation suffix in the Karachay-Balkar language. The structure and origin of the suffix {-(V)wcAn} in Karachay-Balkar is then discussed. Results. When analyzed in the context of historical sound events, it is clearly understood that the suffix {-(V)wcAn} in Karachay-Balkar undoubtedly arose as a result of a merger of the suffix {-(V)G} which was used to form nouns from verbs in the Old Turkish period — and the suffix {+cAn} which forms nouns from nouns and whose exact time of emergence cannot be determined. In brief, it is possible to explain this as {-(V) G} > {-(V)w}+{+cAn} > {-(V)wcAn} with the historical {G}>{w} sound change seen in many Turkic languages. Based on this information, the development of the suffix {-cAn} which is used as a verb conjugation suffix in Khakas and Shor can also be clarified. The analysis into Karachay-Balkar-language literary writings shows that the suffix {-(V)wcAn} is used only as a verb conjugation suffix, losing its noun-forming and participle-forming features. The work also addresses the participle-forming phase of this suffix (before it became a verb-conjugation suffix) and identifies traces of this function in present-day discourses. As a verb conjugation suffix, this suffix is mostly used in expressions in the simple present tense with simple and compound verb conjugations and sometimes, particularly in conditional sentences, as a tense modal expressing the present continuous tense.