The classifi cation system of phraseological units suggested by Russian professor A.V. Koonin is the latest outstanding achievement in the theory of phraseology. This classifi cation is based on the combined structural-semantic principle and subdivided into four classes.
Nominative phraseological units are represented by wordgroups, including the ones with one meaningful word: wear and tear, well and good.
Nominative-communicative phraseological units include word-groups of the type: to break the ice – the ice is broken, that is, verbal word-groups are transformed into a sentence when the verb is used in the Passive Voice.
Phraseological units include interjectional word-groups.
Communicative phraseological units are represented by proverbs and sayings. These four classes are divided into sub-groups according to the type of structure of the phraseological units. “The classifi cation system includes a considerable number of subtypes and gradations and objectively refl ects the wealth of types of phraseological units existing in the language”[ Koonin,2008:44]. It is based on scientifi c and modern criteria and represents an earnest attempt to take into account all the relevant aspects of phraseological units and combine them within the borders of one classifi cation system.

