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

Adjective > Verb, e.g. to dirty, to calm, to empty etc.;
Noun > Adjective, e.g. a stone wall, a cotton cloth etc.;
Modal verb > Noun, e.g. a must;*
Function word > Noun, e.g. too many ifs and buts;
Function word > Verb, e.g. to down, to up etc.;
Affix > Noun, e.g. There are too many ologies and emes in his report.
19. Non-productive ways of word-formation in Modern English.
Back-formation (regressive derivation) is the derivation of new words by subtracting a real or supposed affix from existing words (often through misinterpretation of their structure), e.g. an editor > to edit, enthusiasm > to enthuse etc.
The earliest attested examples of back-formation are a beggar > to beg; a burglar > to burgle; a cobbler > to cobble.
The most productive type of back-formation in present-day English is derivation of verbs from compounds that have either –er or –ing as their last element, e.g. sightseeing > to sightsee; proofreading > to proofread; mass-production > to mass-produce; self-destruction > to self-destruct; a baby-sitter > to baby-sit etc.
Onomatopeia (Gr. onoma ‘name, word’ and poiein ‘the make’) (sound imitation, echoisms) is the formation of words by a more or less exact reproduction of a sound associated with an object producing this sound.
Semantic classification of onomatopeic words:
-sounds produced by people: to babble, to chatter, to giggle, to grumble, to titter, to grumble etc.;
- sounds produced by animals (to moo, to neigh, to mew, to purr etc.), birds (to twitter, to crow, to cackle etc.), insects and reptiles (to buzz, to hiss);
-water imitating sounds: to bubble, to splash etc.;
-sounds imitating the noise of metalic things: to clink, to tinkle etc.;
-sounds imitating a forceful motion: to crash, to whisk, to clash etc.