2. Types of lexical units.

The term unit means one of the elements into which a whole may be divided or analyzed and which possesses the basic properties of this whole. The units of a vocabulary or lexical units are two-facet elements possessing form and meaning. The basic unit forming the bulk of the vocabulary is the word. Other units are morphemes that is parts of words into which words may be analyzed and set expressions or groups of words into which words may be combined.

Words are the central elements of language system, they face both ways: they are the biggest units of morphology and the smallest of syntax. They embody the main structural properties and functions of the language. Words can be separated in an utterance by other such units and can be used in isolation unlike words, morphemes cannot be divided into smaller meaningful units and are functioning in speech only as constituent parts of words. Words are thought of as representing integer concept, feeling or action or as having a single referent. The meaning of morphemes is more abstract and more general than that of words and at the same time they are less autonomous.

Set expressions are word groups consisting of two or more words whose combination is integrated so that they are introduced in speech so to say, ready made as units with a specialized meaning of the whole that is not understood as a mere sum total of the meaning of the element.

Many authors devoted a good deal of space to discussing which of the two the word or the morpheme is to be regarded as the basic unit. Many American linguists (Ch Hockett, Z. Harris) segmented an utterance into morphemes ignoring words. But Soviet lexicologists consider the word as the basic unit.

1. The notion of lexical system

Lexicology studies the recurrent patterns of semantic relationships and of any formal phonological, morphological or contextual means by which they may be rendered. It aims at systematization.

The term system as used in present day lexicology denotes not merely the sum total of English words, it denotes a set of elements associated and functioning together according to certain laws.

The vocabulary of a language is moreover an adaptive system constantly adjusting itself to the changing requirements and conditions of human communication and cultural surroundings. It is continually developing by overcoming contradictions between its state and the new tasks and demands it has to meet.

The elements of the lexical system are characterized by their combinatorial and contrastive properties determining their syntagmatic and paradigmatic relationships.

A word enters into syntagmatic (linear) combinatorial relationship with other lexical units that can form its context, serving to identify and distinguish its meaning.

A word enters into contrastive paradigmatic relations with all other words. Paradigm is the system of all grammatical forms of the word (car, car`s, cars, take, took, taken etc).

The study of the lexical system must also include the study of the words` combinatorial possibilities their capacity to combine with one another in groups of certain patterns, which serve to identify meanings. Most modern research in linguistics attaches great importance to what variously called valency, distributional characteristics, colligations and collocations, combining power or otherwise.