Null subjects and perceptive mode (on the expression of evidentiality in Russian).

The article studies Russian indefi nite-personal and impersonal sentences in their relation to the categories of defi niteness / indefi niteness and evidentiality. The author shows a relation between evidential meanings, types of modus and roles of speaker. The concrete meanings of the mentioned categories (indefi niteness of agent and unavailability of visual perception) can semantically intersect in the perceptive modus (speaker as observer). Semantic interaction between indefi niteness and unreliability of sensor perception is analyzed within text of different genres.