The Indefinite Infinitive is used:
a) if the action it expresses is simultaneous with that of
the finite verb; '
b) with verbs denoting hope, intention, etc. The Indefinite Infinitive expresses an action future with regard to that denoted by the finite verb;
c) with modal verbs the Indefinite Infinitive ofteh ex presses a future action.
The Continuous Infinitive expresses an action in its progress simultaneous with that of the finite verb.
The Perfect Infinitive expresses an action prior to that of the finite verb.
After the verbs should, ought, coidd, sight in the affirmative form as well as after was/were used in modal meaning the Perfect Infinitive shows that the action was not carried out. The same is the meaning of the'Perfect Infinitive combined with the past tense of the verbs to expect, to hope, to intend, etc.
The Perfect Continuous Infinitive expresses an action which lasted during a certain period of time before the action denoted by the finite verb.
, : The infinitive is used: in the Active Voice if the noun
or pronoun it refers to denotes the subject of the action expressed by the infinitive.
The infinitive is used in the Passive Voice if the noun or pronoun it refers to denotes an object of the action expressed by the infinitive.
Функции инфинитива в предложении
§ 178. Инфинитив с зависимыми от него словами образу ет инфинитивную группу:
to learn the poem by heart выучить стихотворение на-
to explain the rule to the объяснить ученикам правило
§ 179. Инфинитив или инфинитивная группа может упот ребляться в предложении в роли подлежащего:
То know him is to trust Зва-гъ его — значит доверять
him. (Wilde) ему.