EN
The subject of the presented article is mental verbs (verbs of knowledge, understanding and thinking) of the modern Russian language, treated in perspective of syntactic valence. The author examines the grammatical forms of realization of propositional argument in the sentences with mental verbs that represent predicate-argument structure P (x, q). All forms of representation of propositional argument are divided into three types: observance, compression and splitting. The author shows that in this area we have to deal with analog reflection of propositional structure, or more or less compression of proposition argument, or its dismemberment and doubling syntactic position. The author takes into account the regularity of the implementation of each grammatical form, quoting the relevant quantitative data. The empirical material has been mostly taken from the Russian Internet Corpus.