The Ministry of Higher and Secondary Specialized Education

CHAPTER I. Lexicology as a linguistic science
1.1. Lexicography is a branch of lexicology
Lexicology is a branch of descriptive linguistics concerned with the linguistics theory and methodology for describing lexical information, often focusing specifically on issues of meaning. Traditionally, lexicology has been mainly concerned with "lexis", i.e lexical collocations and idioms, and lexical semantics, the structure of word fields and meaning components and relations. Until, recently, lexical semantics was conducted separately from study of the syntactic, morphological and phonological properties of words, but linguistic theory in the 1990s has gradually been integrating these dimensions of lexical information.
Lexicology deals with the vocabulary of a language and the properties of the words as the main units of language. The term vocabulary is used to denote the system formed by the sum total of all the words and word equivalent that the language possesses . The term word denotes the basic unit of a given language resulting from the association of a given meaning with a given group of sounds susceptible of a given grammatical employment. The term word equivalent denotes set expression similar to words in so far as they are integrated semantically, not created in speech but introduced onto the act of communication ready-made, and also because they are syntactically treated like single words.
Lexicology came into being to meet the needs of many branches of applied linguistics, namely of lexicography, literary criticism, standardization of terminology and last but not least of foreign language teaching. Its importance in training a would-be teacher of languages is of a quite special character and cannot be overestimated as it helps to stimulate a systematic approach to the facts of vocabulary. It is particularly useful in building up the learner's vocabulary by an affective selection grouping and analysis of new words. It good knowledge of the system of word -formation furnishes a tool helping the student to guess and retain in his memory the meaning of new words on the basis of their motivation and by comparing and contrasting them with the previously learned elements and patterns.
The distinction between the two basically different ways in which language may be viewed, the historical and diachronistic ( gr dia 'through' and chronos 'time') and the descriptive or synchronistic (gr syn together', 'with') is a methodological distinction, a difference of approach, artificially separating for the purpose of study what in real language is inseparable ,because actually every linguistic structure and system exists in a state of constant development.
Synchronic approach deals with the vocabulary as i t exists at a given time, at the present time. The diachronic approach studies the changes and the development of vocabulary in the course of time. Lexicography is a branch of lexicology which studies the vocabulary of a language. Its basic task is to study the origin, the different properties of the vocabulary of a language. It has its own aims and methods of a scientific research.
Lexicology is concerned with the words variable word groups, phraseological units and with morphemes which make up words. Lexicology also studies all kind of semantic grouping. Etymologically the word "lexicology" is a Greek word: "Lexic ^?f means word and " logos" learning.
There are 5 types of lexicology:

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