The specific feature of the structure of the simple (non-derived) verb stem in the Manchu-Tungus languages is its two-aspect character, since it represents simultaneously both terminativity and non-terminativity of action, i. e. the verb stem functions as a two-aspect one, as a stem of both perfective and imperfective aspect expressing the verbal aspectual meanings in the Manchu-Tungus languages are expressed not so much by the temporal characteristics of verbs as by the context and by the semantic word-formative verb classes which are based on the formally expressed modifica-tions or semantic transformations of meanings from the point of view of temporal, quantitative and specific resultative characteristics. The means of coding the aspectual characteristics of an action–aktionsarts – are not analogous to the system of mutually opposed aspect category forms; they function as the means of supplementing the grammatical system and making it possible, even out context, to mark one or another form as a particular aspect form, thereby narrowing the lexical meaning.