1. Introduction

Derivation is affixation, i.e. adding an affix to the stem of a definite part of speech. It is one of the most productive ways of word-building in English. All affixes, as we know, are divided into prefixes and suffixes. Prefixes stand before roots and suffixes stand after roots. But prefixes and suffixes are not only different in their positions in a word, but also in their main functions.

2. Suffixes

The main function of the suffix is to form one part of speech from another (to work – worker, beauty – beautiful). There are some suffixes, however which are exceptions, i.e. they can change the lexical meaning of a word without forming another part of speech, e.g. -ish: if it is added to adjective stems it forms adjectives – green, greenish; -ie: it is added to noun stems and forms nouns with a diminutive meaning – horse –horsie.

Suffixes can be classified according to the part of speech that they form, according to their origin, according to their productivity and frequency of usage.

2.1. Noun Suffixes

1) -er – Germanic origin, forms nouns from verb stems, denotes the agent – worker, teacher; nouns from noun stems or adjective stems of place, denotes 'resident of, one living in' – Londoner, islander;

2) -ing – Germanic origin, forms nouns from verb stems, denotes a process, act, fact, doing, feeling, resulting, accompanying – reading, learning, feeling, covering;

3) -ness – Germanic origin, forms nouns from adjective or verb stems, denotes state, condition, quality or degree – goodness, darkness, forgiveness;

4) –ist – Greek origin, forms nouns from nouns, denotes a person who belongs to some profession, occupation, to some trend in politics, art etc. – violinist, socialist;

5) –ism – Greek origin, forms nouns from nouns or adjectives, denotes teachings, trends in politics, art, systems in social life – socialism, capitalism, modernism;

6) –ess – Romanic origin, forms nouns from noun stems, denotes a feminine being – actress, goddess, lioness;

7) -ment – Romanic origin, forms nouns from verb stems, denotes some action, process – development.

2.2. Adjective Suffixes

1) -ish – Germanic origin, forms adjectives from adjective stems, adds the meaning of approaching the quality expressed by the stem – reddish.

It can also form an adjective from a noun stem, means 'looking like the person expressed by the stem' (depreciatory colouring) – childish, womanish. It can also be met in some words denoting nationality – Irish;

2) -ful – Germanic origin, forms adjectives from noun stems, denotes 'full of, abounding in' – thankful, hopeful, harmful;

3) -less – Germanic origin, forms adjectives from noun stems, denotes 'without, not having, devoid of the quality expressed by the noun stem from which it is formed' – aimless;

4) -ed – Germanic origin, forms adjectives from noun stems, denotes 'possessing the quality expressed by the noun stem from which it is formed' – bearded, gifted;

Most often it is used to form compound-derived adjectives – long-legged;

5) -able (-ible) – Romanic origin, forms adjectives from verb stems, denotes 'capable of doing the action expressed by the stem' – eatable, movable;

It can also form adjectives from noun stems, then it denotes 'characterized by the quality expressed by the stem' – comfortable, honourable, fashionable.