3. Structure of words. Types of morphemes

3.Structure of words. Types of morphemes.
The morphological system of language reveals its properties through the morphemic structure of words.
The main task of morphology is the study of the structure of words. The smallest significant (meaningful) units of grammar are called morphemes.
In traditional grammar the study of the morphemic structure of the word was conducted in the light of the two basic criteria: positional (the location of the marginal morphemes in relation to the central ones) and semantic or functional (the correlative contribution of the morphemes to the general meaning of the word). The combination of these two criteria results in different classifications of morphemes
Criteria of classifying and types of morphemes

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  Function – what they are used for:word- building – worker, form – building ( inflexions) – bigger
  
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  Sphere/ subsystem in which they operate: lexical(roots- child, dog), lexico-grammatical(word-building affixes- friend-friendship), grammatical (form-building affixes or inflexions- I cleaned the floor).
  

Form – positive – worker, dogs and zero morphemes dog – meaningful absence(Grammatical meanings may be expressed by the absence of the morpheme. Compare: book — books. The meaning of plurality is expressed by the morpheme -s. The meaning of singularity is expressed by the absence of the morpheme. Such meaningful absence of the morpheme is called zero morpheme.)
Place - how they are used/ spelled free, bound – dogs, semi-bound – shall ask, discontinuous – is asking (The function of the morpheme may be performed by a separate word. In the opposition work — will work the meaning of the future is expressed by the word will. Will is a contradictory unit. Formally it is a word, functionally it is a morpheme. As it has the features of a word and a morpheme, it is called a word-morpheme. Word-morphemes may be called semi-bound morphemes).
Morphemes are abstract units, represented in speech by morphs. Most morphemes are realized by single morphs: un-self-ish. Some morphemes may be manifested by more than one morph according to their position. Such alternative morphs, or positional variants of a morpheme are called allomorphs: cats, [s], dogs. [z], foxes [iz], oxen-
Morphemic variants are identified in the text on the basis of their co-occurence with other morphs, or their environment. The total of environments constitutes the distribution.
+There may be three types of morphemic distribution: contrastive, non-contrastive, complementary. Morphs are in contrastive distribution if their position is the same and their meanings are different: charming — charmed. Morphs are in non- contrastive distribution if their position is the same and their meanings are the same: learned — learnt Such morphs constitute free variants of the same morpheme. Morphs are in complementary distribution if their positions are different and their meanings are the same: speaks, — teaches. Such morphs are allomorphs of the same morpheme.