Учебное пособие в систематизированном виде содержит необходимые для изучения курса лексикологии английского языка вспомогательные материалы: планы семинаров, определения основных понятий и терминов на английском и русском языках, темы курсовых

Root [ru:t] (or radical) is the lexical nucleus of a word. It remains after the removal of all functional and derivational affixes and does not admit any fur­ther analysis, e.g. needless, precook, fire-eater.
Prefix ['prifiks] is a derivational affix standing before the stem and modi­fying its meaning, e.g. insensitive, ex-minister, reread.
Suffix ['sAfiks] is a derivational affix following the stem and forming a new derivative in a different part of speech (actor, washable, sharpen) or in a different word class within the same part of speech (brohterhood, piglet, young­ster).
Inflection (also inflexion, ending, grammatical suffix, inflectional suffix) is a functional affix. Inflections carry only the grammatical meaning and are relevant only for the formation of word- forms, whereas derivational affixes are relevant for building various types of words. Thus suffixes perform the word­building function (play, player, playful, playfully, playfulness), while the func­tion of inflections is form-changing (play, plays, played, playing).
Lexicalized grammatical affix is a grammatical suffix (inflection) which developed into a derivational suffix. In words like customs “import duties”, colours “a flag/flags of a ship or regiment”, -s does not express plurality. It has the features of a derivational suffix. Another example of a grammatical suffix which became lexicalized is -s in cases like at the dentist's, at my aunt’s. Here it no longer indicates the possessive case, but functions as a derivational suffix denoting the place of activity (as in at the dentist’s) or a place of habitation (as in at my aunt’s).
Free morpheme is a morpheme which coincides with a word-form of an independently functioning word. Free morphemes can be found only among roots, e.g. whole- in the word wholly; brave- in the word bravery.