In the process of studying tropes it is necessary to apply an interdisciplinary approach – a linguistic and literary one. The mechanism of trope formation, no matter what its orientation is – denominative, poetic or expressive – is the same as in case of semantic shifts, on the foundation of associations based on similitude in case of a metaphor and on those of contiguity, in case of metonymy. In this context, the author states that the so-called tropes of a language are, as a rule, semantic shifts and therefore are the subject matter of semasiology. At the same time, the study of poetic tropes belongs to the literary theory and poetics, as well as that of stylistics. However the author does not recommend making a categorical distinction between semantic mutations and poetic tropes, since these two phenomena, although they are distinct, share one and the same mechanism of development. From these considerations, any language study of tropes requires an examination, even partial, of the expressive-poetic aspect of theirs and, conversely, any literary study of tropes needs to be based on thorough analysis of the linguistic mechanism, more correctly mental, of trope formation.