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

Criteria for establishing the directionality of conversion:
historical, e.g. crowd, v (O.E. crudan ‘to press, to hasten, to drive’, 937 AD) > crowd, n ‘a compressed mass of people or things’ 16th c. > ‘any mass of people’;
semantic, i.e. the converted word should be semantically more complex than the base word from which it is derived or is semantically dependent on the latter, e.g. bottle, n > bottle, v; better, adj – better, v;
morphological, i.e. in a homonymous verb-noun pair, the regularly inflected form is derived from the irregularly inflected one, e.g. drink, v > drink, n; sleep, v > sleep, n;
phonetic, i.e. in a homonymous verb-noun pair a stress-shift indicates a derived word, e.g. extráct, v – éxtract, n; pùsh úp, v - púsh-up, n;
frequency of occurrence, i.e. being semantically more complex, derived words have a narrower range of meaning to the effect that they cannot be used in as many contexts as their base words, e.g. water, n > water, v.
Semantic Relations in Conversion
1.Verbs converted from nouns (denominal verbs) denote:
-action characteristic of the object, e.g. dog (n) – to dog (v);
-instrumental use of the object, e.g. screw (n) – to screw (v);
-acquisition or addition of the object, e.g. fish (n) – to fish (v);
-time, e.g. winter (n) – winter (v);
-deprivation of the object, e.g. dust (n) – dust (v).
2.Nouns converted from verbs (deverbial nouns) denote:
-instance or process of the action, e.g. dance (v) – dance (n);
-agent of the action, e.g. help (v) – help (n);
-place of action, e.g. walk (v) – walk (n);
-object or result of the action, e.g. peel (v) – peel (n).
Other Ways of Conversion
Adjective > Noun, e.g. a bitter, a wet, a regular etc.;