Observation on fuctioning of the preposition за in official documents belonging to the end of the XVIIIth century and the beginning of the XIXth century

The author analyzes the semantics and functioning of the non-derivative lexical preposition ЗА in the language of the official documents of the end of the XVIIIth century - the beginning of the XIXth century. The author dwells upon the system of the group meanings of the prepositions analyzing verbs-governors and their nouns-complements. The author shows that the prepositions за (кого, что) and за (кем, чем) are important in the text and style formation in the official documents of the end of the XVIIIth century - the beginning of the XIXth century. They play an active part in the process of the official language normalization. The results of the comparative analysis with modern Russian allow the author to trace the semantic shifts in the meaning of the preposition за requiring the accusative case and the preposition за requiring the ablative case.