3) The category of idiomaticity.

This category is based on the opposition of idiomatic phraseological units, on the one hand, and word-combinations whose meaning is deducible from the meanings of the component words, on the other.

Idiomatic expressions possess the idiomatic globality of nomination, their meaning cannot be deduced from the meanings of the component words. Idioms are the reproducible units of speech, at the same time, they are highly connotative. In connection with this, it is important to remember the difference between the members of this category and the previous one, where the reproducible word-combinations are usually stylistically neutral.

Thus, word-combinations like good student, long speech, pretty girl are non-idiomatic. The word-combinations once in a blue moon, to call a spade a spade, to pull sb's leg are idiomatic. They are charac­terised by the semantic globality of nomination, their meaning is not deducible from the meaning of their constituents.

4) The category of conceptual determination.

This category is based on the opposition of word-combinations which reflect the combination of concepts which, in their turn, correspond to the context of extralinguistic reality and word-combinations the concep­tual basis of which is violated, they are produced for some special reason, usually they are artificial. In other words, a word-combination should have some conceptual motivation. Conceptually undetermined word-combinations are connotative, they are used to produce the function of impact. For example: Together they had seen a forlorn man's figure in a melancholy overcoat. Here the word-combination a melancholy overcoat is not conceptually determined. Usually, we speak of black overcoat, long overcoat etc. This word-combination was coined by the writer to produce the function of impact. Conceptually, the words melancholy and overcoat are undetermined. The same may be said about word-combinations like clean dirt, noiseless smile etc. Most often word-combinations of this type are used in fiction.

5) The category of sociolinguistic determination.

The members of the opposition of this category are sociolinguistically determined and sociolinguistically undetermined word-combinations. It is the social, cultural, historical, lexical-phraseological, conceptual factors, which are very important to understand a word-combination. It is necessary to know the context of the situation in which a particular word-combination was produced: who were the participants of communication, when and where the communication took place etc.

Certainly, one needs to have some background knowledge to under­stand the sociolinguistic aspect of the word-combination. Thus, for example, a word-combination cold war is sociolinguistically determined: one must know the historical period when this word-combination appeared, the political situation in Russia of that period of time, its relationships with other countries etc. Even such simple word-combinations as the white men may be sociolinguistically determined within some particular context.

It is very useful to know that all the categories of word-combinations are very closely interconnected. Practically every word-combination may be either marked or unmarked member of each category. The categorial approach to the study of word-combinations helps to understand their collocational, colligational, conceptual, metasemiotic peculiarities, their place and role in the creation of sentences and discourse