The basic morphological notions are word and morpheme. Word is the smallest naming unit. It’s a sequence of human sounds, conveying a certain notion. Morphemes are the smallest meaningful units, into which a word form can be divided.
The word-form ‘workers’ can be divided into 3 morphemes: ‘work’ expressing the basic lexical meaning of the word; ’er” expressing the doer of the action; ‘s’ is a morpheme, expressing the idea of plurality.
In order to understand what an allomorph is, we will form an opposition – girl – girls, child- children, woman – women. Here morphemes ‘s, en, e’ have the same grammatical meaning, because they express plurality. They are allomorphs, that is variants of a morpheme of plurality.
Allomorph is a variant of a morpheme which occurs in certain environments.
Thus, the morpheme is a group of one or more allomorphs. We can distinguish root morphemes and affixal morphemes.
Semantically morphemes fall into two classes: root-morphemes and non-root or affixation al morphemes. Roots and affixes make two distinct classes of morphemes due to the different roles they play in word-structure.
root-morpheme is the lexical nucleus of a word, it has an individual lexical meaning shared by no other morpheme of the language.
A f f i x e s are classified into prefixes and s u f f i xes: a prefix precedes the root-morpheme, a suffix follows it. Affixes besides the meaning proper to root-morphemes possess the part-of-speech meaning and a generalized lexical meaning.
Structurally morphemes fall into three types: free morphemes, bound morphemes, semi-free (s e m i -bound) morphemes.
A great many root-morphemes are free morphemes, for example, the root-morpheme friend – of the noun friendship is naturally qualified as a free morpheme because it coincides with one of
the forms of the noun friend.
A bound morpheme occurs only as a constituent part of a word. Affixes are, naturally, bound morphemes, for they always make part of a word, e.g. the suffixes -ness, -ship, -ize, etc., the prefixes un-, dis-, de-, etc. (e.g. readiness, comradeship, to activize; unnatural, to displease, to decipher). Semi-bound (semi-free) morphemes1 are morphemes that can function in a morphemic sequence both as an affix and as a free morpheme. For example, the morpheme well and half on the one hand occur as free morphemes that coincide with the stem and the word-form in utterances like sleep well, half an hour, on the other hand they occur as bound morphemes in words like well-known, half-eaten, half-done.
Morph. structure : Preff+root+lex suff+ gramm suff