Branches of linguistics. Synchronic vs diachronic approaches to the language study. Lexicology – ‘the science of the word’

Depending on the number of morphemes, words are divided into:
monomorphic are root-words consisting of only one root-morpheme, i.e. simple words, e.g. to grow, a book, white, fast etc.
polymorphic are words consisting of at least one root-morpheme and a number of derivational affixes, i.e. derivatives, compounds, e.g. good-looking, employee, blue-eyed etc.
According to their functions and meaning, affixes fall into:
derivational, e.g. suffixes: abstract-noun-makers
14. General description of word-formation in Modern English. Productive and nonproductive means.
Word-formation (word-building) is the creation of new words from the material available in the language on certain formulas and patterns.
Functions of word-formation:
nominative function;
communicative function.
Word-formation results in:
development of the vocabulary (92,5% of neologisms in Modern English result from word-formation);
re-categorisation (derivatives belong to different word classes).
Word-family is a set of words that all share a common root, e.g. graceful, ungraceful, gracefulness, to disgrace, disgracefully, disgraceful, disgrace, disgracefulness, gracelessly, graceless etc.
Productivity is the ability to form new words after existing patterns which are readily understood by speakers of a language.
Productive means:
Affixation
Word-composition
conversion
shortening
Non-productive means:
back-formation
onomatopoeia
sound and stress interchange
sentence condensation
15. Affixation. Classifications of affixes. Productive and non-productive affixes, dead and living affixes.
Affixation (progressive derivation) is the formation of words by adding derivational affixes to stems.
Prefixation is the formation of words with the help of prefixes; does not change part of speech; is more typical of verb-formation (42%), e.g. a pretest, to coexist, to undo, impossible, asleep, to rewrite etc.
Suffixation is the formation of words with the help of suffixes; can change part of speech; is characteristic of noun-, adjective- and adverb-formation, e.g. an employee, childish, quietly, to specify etc.
Synchronic vs diachronic differentiation of affixes: