324. A peculiar infinitive construction often replaces a that-clause as the object of a verb. Thus,—

I wished {that he should go. | him to go.}

In the first sentence, the noun clause that he should go is the object of wished; in the second, this clause is replaced by him to go, but without any change in meaning. This expression consists of two parts:—(1) him, a pronoun in the objective case, which replaces the subject he; and (2) an infinitive to go, which replaces the predicate should go. Thus it is plain that him to go is also a noun clause, of which him is the subject, and to go the predicate. Such an expression is called an infinitive clause.

325. A kind of clause, consisting of a substantive in the objective case followed by an infinitive, may be used as the object of certain verbs.

Such clauses are called infinitive clauses, and the substantive is said to be the subject of the infinitive.

The subject of an infinitive is in the objective case.

Infinitive clauses are used (1) after verbs of wishing, commanding, advising, and the like, and (2) after some verbs of believing, declaring, and perceiving.[39] Thus,—

After a few verbs the infinitive without to is used in infinitive clauses.