The article is the first attempt to single out and describe categorical features of the fixed phrase scheme «Самое + V inf!». The status of the investigated syntactic model as a sentence of the phraseologized type was confirmed. The fixed phrase scheme expresses two enantiosemic meanings and is characterized by the existence of two structural variants. The first one is represented by the compulsory unchangeable component самое in combination with infinitive; herewith the initial meaning of the lexeme самое is absolutely de-actualized, both compulsory components do not have paradigmatic characteristics. The non-grammatical combination of the defining pronoun with the infinitive determines a high degree of phraseologization of the syntactic sentence model. The inner form of the lexeme самое is modern when the compulsory component самое stands with a noun, which leads to the maintaining of its morphological paradigm. The fixed phrase scheme does not possess syntactic paradigm. The idiomaticity of the first fixed phrase scheme variant is determined by the nonderivability of the meaning «expediency / inexpediency of smth» from the meanings of the separate lexical components; the nonderivability of the modus meaning of the component (semes «approval», «intensity», «expressivity»), the nonderivability of the syntactic meaning of the sentence model that is formally represented by the combination of the defining pronoun and the infinitive, contradictory to the grammatical norms, as well as of the stylistic seme «colloquialism». Besides, when this sentence is analyzed logically we can distinguish two propositions («now it is time» and «to learn»), which are represented by the simple sentence. Thus, the syntactic seme represented the meaning of structural and semantic sentence type is also idiomatic. While realizing the second, enantiosemic meaning of the fixed phrase scheme, the semes «negation», the modus component (semes «irony», «expressivity», etc.), syntactic seme and colloquial styleme are idiomatic. All these make the fixed phrase scheme the effective tool of communication in the conditions of the colloquial speech.