Etymology is a branch of lexicology studying the origin of words. Etymologically, the English vocabulary is divided into native and loan words, or borrowed words. A native word is a word which belongs to the original English word stock and is known from the earliest available manuscripts of the Old English period. A borrowed word is a word taken over from another language and modified according to the standards of the English language.

Native words are subdivided into two groups:

1) words of the Common Indo-European word stock

2) words of the Common Germanic origin

Words of the Indo-European stock have cognates (parallels) in different Indo-European languages: Greek, Latin, French, Italian, Polish, Russian and others:

father (OE fæder, Gothic fadar, Swedish fader, German Vater, Greek patér, Latin páter, French pere, Persian pedær, Sanscrit pitr)

Words of the Common Germanic stock have cognates only in the Germanic group: in German, Norwegian, Dutch, Icelandic, etc.:

to sing (OE singan, Gothic siggwan, German singen)

Numerically the Germanic group is larger. Thematically these two groups do not differ very much. Words of both groups denote parts of the human body, animals, plants, phenomena of nature, physical properties, basic actions, etc. Terms of kinship, the most frequent verbs and the majority of numerals belong to the Common Indo-European word stock. Many adverbs and pronouns are of Germanic origin.

Native words constitute about 25 percent of the English vocabulary, but they make up 80 percent of the 500 most frequent words. Almost all native words belong to very important semantic groups. They include most of the auxiliary and modal verbs, pronouns, prepositions, numerals, conjunctions, articles. Besides high frequency value words of the native word stock are characterised by the following features:

· simple structure (they are often monosyllabic)

· developed polysemy

· great word-building power

· an ability to enter a great number of phraseological units

· a wide range of lexical and grammatical valency

· stability

Conversion.

Conversion is a characteristic feature of the English word-building system. It is also called affixless derivation or zero-suffixation. The term «conversion» first appeared in the book by Henry Sweet «New English Grammar» in 1891. Conversion is treated differently by different scientists, e.g. prof. A.I. Smirntitsky treats conversion as a morphological way of forming words when one part of speech is formed from another part of speech by changing its paradigm, e.g. to form the verb «to dial» from the noun «dial» we change the paradigm of the noun (a dial,dials) for the paradigm of a regular verb (I dial, he dials, dialed, dialing). A. Marchand in his book «The Categories and Types of Present-day English» treats conversion as a morphological-syntactical word-building because we have not only the change of the paradigm, but also the change of the syntactic function, e.g. I need some good paper for my room. (The noun «paper» is an object in the sentence). I paper my room every year. (The verb «paper» is the predicate in the sentence).

Conversion is the main way of forming verbs in Modern English. Verbs can be formed from nouns of different semantic groups and have different meanings because of that, e.g.

a) verbs have instrumental meaning if they are formed from nouns denoting parts of a human body e.g. to eye, to finger, to elbow, to shoulder etc. They have instrumental meaning if they are formed from nouns denoting tools, machines, instruments, weapons, e.g. to hammer, to machine-gun, to rifle, to nail,

b) verbs can denote an action characteristic of the living being denoted by the noun from which they have been converted, e.g. to crowd, to wolf, to ape,

c) verbs can denote acquisition, addition or deprivation if they are formed from nouns denoting an object, e.g. to fish, to dust, to peel, to paper,

d) verbs can denote an action performed at the place denoted by the noun from which they have been converted, e.g. to park, to garage, to bottle, to corner, to pocket,

e) verbs can denote an action performed at the time denoted by the noun from which they have been converted e.g. to winter, to week-end .

Verbs can be also converted from adjectives, in such cases they denote the change of the state, e.g. to tame (to become or make tame) , to clean, to slim etc.

Nouns can also be formed by means of conversion from verbs. Converted nouns can denote:

a) instant of an action e.g. a jump, a move,

b) process or state e.g. sleep, walk,

c) agent of the action expressed by the verb from which the noun has been converted, e.g. a help, a flirt, a scold ,

d) object or result of the action expressed by the verb from which the noun has been converted, e.g. a burn, a find, a purchase,

e) place of the action expressed by the verb from which the noun has been converted, e.g. a drive, a stop, a walk.

Many nouns converted from verbs can be used only in the Singular form and denote momentaneous actions. In such cases we have partial conversion. Such deverbal nouns are often used with such verbs as : to have, to get, to take etc., e.g. to have a try, to give a push, to take a swim .