Mongolian belongs to the Mongolic languages. The delimitation of the Mongolian language within Mongolic is a much disputed theoretical problem, one whose resolution is impeded by the fact that existing data for the major varieties is not easily arrangeable according to a common set of linguistic criteria. Such data might account for the historical development of the Mongolian dialect continuum, as well as for its sociolinguistic qualities. Though phonological and lexical studies are comparatively well developed, the basis has yet to be laid for a comparative morphosyntactic study, for example between such highly diverse varieties as Khalkha and Khorchin.