Representation of the category of certainty–uncertainty by the forms of accusative and genitive cases in the Russian language and their Persian equivalents

Purpose. The purpose of this study is to present one of the main means of expressing the category of certainty-indeterminacy, or rather the opposition of the forms of the genitive and accusative cases, its semantics and ways of expressing them in Persian. The relevance of the study lies in the fact that Iranian students make persistent mistakes in Russian due to failure to distinguish between the forms of accusative and genitive cases of definiteness and uncertainty, due to the lack of a case system in the Persian language.Results. The research material consists of examples selected by the authors from various types of scientific works and Russian language textbooks for foreign students. In addition, the research material included examples from the personal files of the authors’ mistakes, collected during monitoring of the educational process and the transfer process of Russian studies students at universities in the Islamic Republic of Iran. The study is based on such research methods as qualitative analysis, continuous sampling method and comparative method.Conclusion. It was revealed that the opposition of the forms of the accusative and genitive cases, as the main factor in the spread of errors in the use of RFL by Iranian students both in the learning process and in the translation process, is transmitted in Persian by lexical and grammatical means. As a result, a classification of shades of opposition of the accusative and genitive forms of the categories of definiteness and uncertainty and their correlates in the Persian language was proposed.