The dependency grammars for such languages as Russian usually treat the prepositions in combination with subordinate nouns as major elements as if the case form in the prepositional construction had some self-contained meaning subjected to the regular transformation. This scheme may be valid for languages with restricted declensional paradigms, however, in Russian due to the fact that several case forms are combined with primary prepositions the specific system of joint interpretation of a preposition and a case form has resulted in a system of syntaxemes, minimal syntactical items designed to express semantic notions according to the lexical nature of the governor words in the texts.
The syntaxeme structure being the part of the grammatical system has a number of vague manifestations in modern Russian texts which may be acquired from the corpus statistics. The evidence of syntaxeme structure are presented in the ranks of collocations with rough semantic classes of governee nouns with frequent primary prepositions, on the one hand, and the semantico-syntactic role specification of the prepositional construction in the sentence, from the other hand.
This structure has several levels of syntactic abstraction. The syntaxeme level is the central layer showing the most frequent combinations of prepositions with noun forms of subordinate semantic classes. Several syntaxemes may be united into the group of so-called semantic rubrics, more or less equal to the semantico-syntactic arguments or roles of the construction in the sentence. The witnesses of semantic rubrics in the texts are usually expressed by secondary prepositions. The bottom level of syntaxeme units is determined by subtle sense variants of the construction produced by the marked semantic classes of governor words of prepositions and governee nouns, which resulted in the merged synonymic and quasi-synonymic usage of prepositional constructions.