Non-finite verb forms in Turkic exhibit syncretism, not multifunctionality

Non-finite verbs in Turkic are typically categorised as participles, converbs, and sometimes infinitives, with multiple uses of a form within one category considered to constitute multiple functions. This multifunctionality approach predicts that all non-finite verb forms within each of the categories should have the same range of syntactic functions. We show that this is not the case. Based on analysis of a representative set of Turkic languages (Kazakh, Kyrgyz, Sakha, Tatar, Turkish, and Tuvan), we propose a categorisation based on morphological and syntactic properties of non-finite verbs, resulting in four categories: verbal nouns, verbal adjectives, verbal adverbs, and infinitives. Under this approach, forms that are typically labelled as participles end up categorised as verbal nouns, verbal adjectives, or both, and forms that are typically labelled as converbs end up categorised as verbal adverbs, infinitives, or both. Some forms even span these two divisions. When a non-finite verb form appears to exist in multiple categories, we consider this to be a case of syncretism; this is, there is a member of one category that has the same form as a member of another category. We propose historical trajectories that may have led to the types of situations that are attested, examine the limitations of this approach, and discuss its wider implications.