Similarity and difference between a set-expression and the word. Various ways of classifying set expressions in English.

There are different ways of classifying phraseological units in Eng­lish: semantic, structural, contextual, etymological (genetic), styli­stic and others. The semantic classification was introduced by acade­mician V. V. Vinogradov. It is based on the relation of the meaning of the whole unit and the meanings of its components, on the degree of semantic cohesion between the components of a phraseological unit. There are three types of phraseological units according to the given classification: phraseological fusions (idioms), phraseological unities and phraseological combinations.

In Professor Smirnitsky’s classification structural and semantic principles are combined. He distinguishes three types of stable com­binations in the language: idioms, phraseological units, traditional phrases. Professor Smirnitsky singles out two semantico-structural types of phraseological units: one-summit phraseological units and two-summit (or multi-summit) phraseological units.

N. N. Amosova introduced the contextological principle of di­stinguishing phraseological units. Context is a combination of a se­mantically dependent word with an indicator. In her classification N. N. Amosova subdivides phraseological units into phrasemes and idioms.

If we regard a set phrase as a word equivalent and pay attention to the function it fulfills in speech, set expressions can be subdivided in­to: verbal, nominal, attributive, adverbial, conjunctional, interjectio- nal, prepositional set phrases. Within the functional classes set ex­pressions are often classified according to their structural type, which may be represented by their distributional formulas.

In A. V. Koonin’s classification classes of phraseological units are distinguished on the basis of the function of phraseological units in the course of communication which is determined by their structural and semantic peculiarities. Koonin’s structural-semantic-functional phraseological units are subdivided into: nominative, nominative- communicative, interjectional, communicative.

According to the etymological principle set phrases may be divided into native and borrowed. The genetic classification (which is sometimes called «thematic») reveals the origin of the set phrase.