Voice is the main classificatory morphological category in the Kartvelian languages. Morphological patterns of verbs, types of conjugation, as well as syntactical constructions, are differentiated according to voice. In this respect, all the Kartvelian languages follow an essentially identical principle. Any deviation from this general principle constitutes a dialectal innovation, arising mainly on the basis of unification. The relative abundance of dialectal variants should be explained by the fact that in various dialects different forms undergo unification.