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

From the viewpoint of their origin homonyms are classified into:
-historical homonyms which result from the breaking up of polysemy; then one polysemantic word will split up into two or more separate words (see the examples on the divergence of word meanings);
-etymological homonyms, i.e. words of different origin which come to be identical in sound or / and in spelling (see the examples on the convergent sound development).
From the point of view of the correlation between the sound form and the graphic forms, homonyms are classified into:
homonyms proper (perfect, absolute, full) are words identical both in pronunciation and in spelling but different in meaning, e.g. back n. ‘part of the body’ - back adv. ‘away from the front’ - back v. ‘go back’; bear n. ‘animal’ - bear v. ‘carry, tolerate’;
homographs are words identical in spelling but different in sound and meaning e.g. bow /bəu/ - bow /bau/; lead /li:d/ - lead /led/; homophones are words identical in sound but different in spelling and meaning: son – sun; pair – pear; air - heir, buy - by, him - hymn, steel – steal; storey – story;
homoforms are words identical in some of their grammatical forms: bound, v. ‘to jump, to spring’ - bound (past participle of bind); found, v. ‘establish’ - found (past participle of find);
capitonyms are words that share the same spelling but have different meanings when capitalised, e.g. polish, v. ‘to make shiny’ - Polish, adj. ‘coming from Poland’; Boxing Day (26th of December) – boxing ‘ a kind of sport’.
The classification based on the distinction between homonymy of words and homonymy of individual word-forms (suggested by Prof. Smirnitskiy).
Full homonyms are two or more words which belong to the same part of speech and coincide in all their forms, i.e. their paradigms are identical, e.g.
blow, v. ‘to send out a strong current of air’ - blow, v. ‘to produce flowers’; mole, n. ‘a small, furry, almost blind animal that digs holes and passages underground to live in’ – mole, n. ‘a small, dark brown, slightly raised mark on a person’s skin’;