1.1. Non-Finites: General Characteristic.
Every verb stem (except a few defective verbs) takes both finite and non-finite forms: the syntactical function of the finite forms is that of the finite predicate; the non-finite forms serve various syntactic functions other than that of the finite predicate.
Non-Finites are the forms of the verb occupying intermediary lexico-grammatical position between the verb and the non-processual parts of speech. The mixed features of these forms are revealed in the spheres of the part-of-speech characterisation (their meaning, structural marking, combinability, and syntactic functions).
Their fundamental grammatical meaning is processual and their essential syntactic functions reveal verbality (ability of verbids to take adjuncts expressing the recipients, attendants, and addressees of the process).The processual (verbal) meaning is expressed by them in a substantive or adjectival-adverbial way. Non-finites are characterised by the following features:
1) they are formed by special morphemic elements which do not express either grammatical time or mood.
2) they can be combined with verbs like non-processual lexemes
3) they can be combined with non-processual lexemes like verbs .
4) they have no immediate means of expressing time-mood categorial semantics.
5) they express the so-called ‘secondary’ or ‘potential’ predication, forming syntactic complexes directly related to certain types of subordinate clauses (possess the function of semi-predication):
Have you ever had anything caught in your head? = Have you ever had anything that was caught in your head?
He said it half under his breath for the others not to hear it. = He said it half under his breath, so that the others couldn't hear it.
Four forms of the English non-finites:
1) the infinitive,
2) the gerund,
3) the present participle,
4) the past participle.