Synonymic relations of causal prepositions in Russian literary language of the 19th century

The article is devoted to studying the prepositional synonymy in the Russian literary language of the 19th century. The work studies structures in which prepositions are a means of expressing causality - conceptual and linguistic category presented as patrimonial relative to species categories of causes, purpose and concessions. The definition of the term preposition-synonym is given. In view of lexical and morphological differentiation of prepositional synonymy in this research the lexical synonymy is analyzed. The work is based on texts of various genres of the 19th century represented in the Russian National Corpus. It characterizes some ranks of synonymic causal prepositions in the Russian literary language of the 19th century: the analysis of the use of synonyms in different contexts, combined with one of the particular values of causality - the reasons, purpose, concessions determined specifics of using separate units; it identifies some trends in the development of synonyms for over a century. The main trends in the development of synonymic ranks of causal prepositions in the 19th century are revealed. Some lexical units fade; others are established and continue to expand the field of their application. Thus, on the basis of the material studied, we can conclude that the development of means of synonymous semantic causality expression in the 19th century followed the path of verbal marking of more subtle shades of causality.