The Compound Verbal Predicate
The compound verbal predicate is of two kinds: modal and aspect(ive).
3a) The Compound Verbal Modal Predicate
This kind of predicate consists of a modal component and an infinitive. The modal components can be expressed by:
1. a modal verb, e.g.: I can’t read. ”She must go to him” The enemy shall not pass.
2. the verbs “be” and “have” in modal meaning, also “have got” in the meaning of necessity, e.g.: They were to marry in the autumn. Why did he have to leave her? I’ve got to express my likes and dislikes.
3. an equivalent of a modal verb “to be (un)able”, “to be capable”, “to be allowed”, “to be permitted”, “to be obliged”, “to be compelled”, “to be willing”, “to be anxious”, “to be eager”, e. g.: He was only anxious to forget. Every minute or so he was compelled to rest. And children werealways willing to play cricket with him.
4. a notional verb with a modal meaning. Here belong the verbs “to hope”, “to want”, “to desire”, “to wish”, “to long”, “to expect”, “to intend”, “to try”, “to endeavour”, etc., e.g.: He almost expected to hear a price. He wanted not to stopever. I long to see her.
5. the combination “to be going to” denoting intention, e.g.: He’s going to buy her some shoes.
6. the phraseological units “had better (best)”, “had rather”, would rather (sooner), e.g.: Hadn’t we better call him? She said she would rather have a flowered summer frock.
The infinitive in the function of a part of a compound verbal modal predicate is used after a modal component.
3b) The compound verbal aspect(ive) predicate
This kind of predicate consists of two components. The first is a finite verb denoting: a) beginning, b) duration, c) repetition, d) cessation, or end of an action. The second component is an infinitive or gerund. To the verbs of the four mentioned groups belong, in particular:
1. beginning of an action: begin, start, commence, which are followed by both an infinitive and a gerund; come, grow, which are combined only with an infinitive, e.g.: He began to sing. She started to undress.
2. duration of an action: keep (on), go on, which are followed only by a gerund; continue, which is followed by both an infinitive and a gerund, e.g.: His mother continued to sway. Al kept working out.
3. repetition of an action: used to and would followed by an infinitive only, e.g.:
Where did he use to hang out? Now and then the old man would correct her pronunciation and she would repeat a word.
4. cessation, or end of an action: stop, give up, leave off, finish, which are followed only by a gerund, cease, which combines both with an infinitive and a gerund, e.g.: He ceased, however, to take out and replace the letter. She had given up calling him sir. She hadn’t stopped talking.
The infinitive in the function of a part of a compound verbal aspective predicate is used after an aspective component denoting beginning, duration, repetition or cessation of an action.
THE SUBJECTIVE INFINITIVE CONSTRUCTION
(traditionally called the Nominative-with-the-Infinitive Construction) is а construction in which the infinitive is in predicate relation to а noun in the Common case or а pronoun in the Nominative case.
In the sentence
The girl (she) was seen to leave the house
the relation between the girl (she) and the infinitive to leave is that of secondary subject and secondary predicate and the whole construction the girl (she) ... to leave is the complex subject to the predicate of the sentence was seen.
What was seen was the girl in the action of leaving the house.