Types of morphemes.
A morpheme is the smallest indivisible meanful language unit. Like a word a morpheme is a two-facet unit. It has a certain meaning and certain sound or outer form. Unlike a word a morpheme is not autonomous because they can occur in speech only as constituent part of a word.
According to their role and meaning morphemes are subdivided into root-morpheme or just roots and affixation morphemes or affixes.
Roots are the lexical nuclei the semantic sentence of the words. Roots have a concrete lexical meaning and are common part of a word-family (group of words with one and the same root).
to read – reader – reading – readable – to reared
Root – morphemes posses all types of meaning: lexical (ran, fly, move), differential (bookcase, bookcounter) and distributional meaning (singer, movement).
According to their position affixes are classified into prefixes and suffixes.
According to their meaning and function affixes are subdivided into grammatical and derivational.
Grammatical affixes are suffixes. Derivational affixes are both prefixes and suffixes.
Suffixes serve to form new grammatical form of the word.
Derivational affixes serve to built new words.
Suffixes are studied in Grammar and derivational affixes are studied in Lexicology.
Structurally morphemes fall into free and bound morphemes.
Free morphemes are those which coincide with separate words (book, chair, ect).
Affixes are bound morphemes.
In English there are some root-morphemes which are not free ( horror, anglo-saxon).
Also in English there are semi-free or semi-bound morphemes (man – servant – gentleman).
Affixes should not be confused with combining elements (tele, photo, graph, vision)
A morpheme may have several positional or graphic variants (allomorphs).
to please – pleasant – pleasure