Antonyms are words belonging to the same category of parts of speech and expressing contrary or contradictory notions. Antonyms, from the Greek anti (opposite) and onoma (name) are word pairs that opposite in meaning, such as hot and cold, fat and skinny. According to the defi nition given by I.V. Arnold it seems to be “antonyms may be classifi ed as two rarely more words belonging to the same part of speech identical in style and nearly identical in distribution, associated and used together in opposite meanings” [Arnold, 2012:57]. As for interpretation of R.S Ginzburg “the term ‘antonyms’ can be characterized by semantic polarity of denotational meanings or meaning and interchangeable in some context” [Ginzburg, 1985:84]. Polysemantic words may have different antonyms depending on the meaning. For example, the adjective dull has the antonyms interesting, amusing, entertaining for its meaning of “defi cient in interest”, clever, bright, capable for its meaning of “defi cient in intellect” and active for the meaning of “defi cient in activity” etc. Antonyms form mostly pairs, not groups like synonyms: above – below, absent – present, alike – different, bad – good.

Antonymy is not distributed among the categories of parts of speech. Most antonyms are adjectives they are only natural because qualitative characteristics are easily compared and contrasted. 

E.g.:high – low, old – young, wide – narrow, strong – weak etc. Verbal pairs of antonyms are fewer in number. Here are some of them: to lose – to fi nd, to open – to close, to accept – to reject etc. Nouns are not rich in antonyms, but even so some examples can be given: good – evil, joy – grief, love – hatred, friend – enemy.

Antonymic adverbs can be subdivided into two groups: a) adverbs derived from adjectives: warmly – coldly, merrily – sadly, loudly – softly; b) adverbs proper: now – then, here – there, ever – never, up – down. Antonyms are words grouped together on the basis of the semantic relations of opposition possessing its own structure, where the antonyms can be divided into antonyms of the same root, e.g. to dress – to undress, employed – unemployed, human –inhuman and antonyms of different roots: rich – poor, strong – weak. The famous scientist V.N. Komissarov in his dictionary of antonyms classifi ed them into two groups: “absolute or root antonyms have different roots (late – early, old – young) and derivational antonyms have the same roots and different affi xes [Komissarov, 2000: 36] (to please – to displease, expensive – inexpensive, prewar – postwar). Semantically, absolute antonyms can be subdivided into antonyms:

 proper where opposition is gradual, it includes several elements characterized by different degrees of the same property, e.g.

cold, cool – warm, hot; large, big – little or small.

 complementarity is a binary opposition, it may have only two members, the denial of one member of the opposition implies the assertion of the other, e.g. dead – alive, single – married, male – female.

 сonverseness denote one and the same referent from different points of view, e.g. to sell – to buy, to give – to receive.

The regular type of derivational antonyms contains negative prefi xes: (im-, il-, in-, ir-, un-, dis-, non-), for example, experienced – inexperienced, logical – illogical, convenient – inconvenient. Sometimes they are formed by means of suffi xes: (-ful and -less).The number of antonyms with the suffi xes (-ful and -less) is not very large, and sometimes even if we have a word with one of these suffi xes its antonym is formed not by substituting (-ful by – less), e.g. successful – unsuccessful, selfl ess – selfi sh. The same is true about antonyms with negative prefi xes, e.g. «to man» is not an antonym of the word «to unman», «to disappoint» is not an antonym of the word «to appoint». The difference between derivational and root antonyms is not only in their structure, but in semantics as well. Derivational antonyms express contradictory notions, one of them excludes the other, e.g.

active – inactive. Absolute antonyms express contrary notions and can be arranged in a group of more than two members, e.g. the antonyms of the adjective ugly – plain, good-looking, pretty, beautiful. Professor L. Lipka gives the type which he calls: “directional opposition up/down, consequence opposition learn/know, antipodal opposition North/South, East/West” [Lipka, 1994: 151]. It is based on contrary motion, in opposite directions. The pairs come/go, arrive/ depart involve motion in different directions. In the case up/down we have movement from a point P. In the case come/go we have movement from or to the speaker. Professor L. Lipka also points out non-binary contrast or manymember lexical sets. He gives serially ordered sets, such as “scales (hot, warm, tepid, cool, cold); colour words (black, grey, white); ranks (marshal, general, colonel, major, captain) There are gradable examination marks: excellent, good, average, fair, poor [Lipka, 1994, 152]. The type of opposition can be met in qualitative adjectives and their derivatives, e.g. beautiful – ugly, to beautify – to uglify, beauty – ugliness. It can be also met in words denoting feelings and states, e.g. respect – scorn, to respect – to scorn, respectful – scornful, to 

live – to die, alive – dead, life – death. It can be also met among words denoting direction in space and time, e.g. here – there, up – down, now – never, before – after, day – night, early – late etc. If a word is polysemantic it can have several antonyms, e.g. the word bright has the antonyms dim, dull, sad.

Synonyms and Antonyms form an integral part of the English language. Acquaintance with the vocabulary of the English language is a necessity for effective expression either in written or in an oral form. The synonym is a word or a phrase that means the same as another word or a phrase. The antonym is a word or phrase that is opposite in meaning to a particular word or phrase in the same language.