The main unit of the lexical system of a language resulting from the association of a group of sounds with a meaning is a word. This unit is used in grammatical functions characteristic of it. It is the smallest language unit which can stand alone as a complete utterance. A word, however, can be divided into smaller sense units - morphemes. The morpheme is the smallest meaningful language unit. The morpheme consists of a class of variants, allomorphs, which are either phonologically or morphologically conditioned.