The paper analyzes the fundamental syntactic opposition between coordination and subordination against the material of converb clauses in three Dargi dialects: Icari, Qunqi and Ashti. As a result of this research, variance of some converbs with regard to coordination/subordination has been observed: like in many other languages, subordination correlates with causal semantics and same-subject use of the converb. The border between coordination and subordination, however, is not clearly distinct in such cases, and variance is not observed for all of the relevant tests employed. This leads us to the conclusion that such a situation cannot be described in the framework of a pragmatic definition of coordination and subordination, which is used in some functionalist approaches. Also, based on the analysis of the data of closely related dialects, I propose a hypothetical possible path of diachronic evolution of the converb constructions under discussion.