Statement of the problem. Russian and Mongolian languages are unrelated, multi-structured, differing from each other in all linguistic aspects, first of all, in grammar. However, unfortunately, their systemic comparative description is still lacking. Besides, the Russian language which used to be compulsory for study as a foreign language in all educational institutions nowadays is studied only in the 7th-9th grades of comprehensive schools. All this negatively affects the Russian language teachers training, many of whom have linguistic and speech competencies insufficiently formed; therefore, in our opinion, the approach to teaching Russian grammar in the Mongolian audience should be improved. The purpose of the article is as follows: on the basis of the comparative characteristics of verbs, nouns and prepositions, to predict the most acute zones of interference in the construction of syntactic structures and to help avoid negative mutual influence. As a result, the main areas of interference are determined. This is, firstly, the structural mismatch of Russian one-piece sentences with their Mongolian equivalents and, secondly, syntactic models with determinants in general and with subject-object ones, in particular. Knowing this will allow the teacher, when planning, to devote more time to these structures, consistent continuous work with them, which ultimately will help the formation of linguistic and speech competence.