Say about the lexico-grammatical grouping of English vocabulary and its types.

Lexico-grammatical grouping consists in classifying words not in isolation but taking them within actual utterances. Here the first contrast to consider is the con­trast between notional words and form or functional words. Actually the definition of the word as a minimum free form holds good for notion­al words only. It is only notional words that can stand alone and yet have meaning and form a complete utterance. They can name dif­ferent objects of reality, the qualities of these objects and actions or the process in which they take part. In sentences they function syntactically as some primary or secondary members.

Form words, also called functional words, empty words or auxiliaries (the latter term is coined by H. Sweet), are lexical units which are called words, although they do not conform to the definition of the word, because they are used only in combination with notional words or in reference to them. This group comprises auxiliary verbs, prepositions, conjunctions and relative adverbs. Primarily they express grammatical relationships between words. This does not, however, imply that they have no lexical meaning of their own.

The borderline between notional and functional words is not always very clear and does not correspond to that between various parts of speech. Thus, most verbs are notional words, but the auxiliary verbs are clas­sified as form words. It is open to discussion whether link verbs should be treated as form words or not. The situation is very complicated if we consider pronouns. Personal, demonstrative and interrogative pro­nouns, as their syntactical functions testify, are notional words; reflexive pronouns seem to be form words building up such analytical verb forms as warmed myself, but this is open to discussion. As to prop-words (one, those, etc.), some authors think that they should be con­sidered as a separate, third group.

Next type of grouping is subdivisions of parts of speech into lexico-grammatical groups. By a lexico-grammatical group we un­derstand a class of words, which have 1) a common lexico-grammatical meaning, 2) a common paradigm, 3) the same substituting elements and pos­sibly 4) a characteristic set of suffixes rendering the lexico-grammatical meaning. These groups are subsets of the parts of speech, several lexico-grammatical groups constitute one part of speech. Thus, English nouns are subdivided approximately into the following lexico-grammatical groups: personal names, animal names, collective names (for people), collective names (for animals), abstract nouns, material nouns, object nouns, proper names for people, toponymic proper nouns.