The article deals with the problem of teaching Russian idioms to translators, describes the method of idioms translation as a traditional way of their semantization in the classroom. The author pays special attention to the category of “inner form”, the bearer of cultural connotation and the basis for establishing similarities and differences in the meaning of idioms in different languages. The sequence of steps for applying the inner form of idioms analysis as an alternative way of their semantization, which contributes to the reduction of sociocultural errors of translators and the development of language guessing, creative thinking, is described in detail.