The article is devoted to the description of lexeme «truth» functioning features entering different speech genres. The word «truth» is referred to the group of discourse words providing speech coherence, reflecting the process of interaction between the speaker and listener, as well as conveying attitude of the speaker to what has been said. The study considers broad understanding of discourse words as structural components of the speech genre that realize illocutionary functions and are associated with speech steps of the speaker in the creation of genre.