In addition to the moods there are three special verb forms to consider: infinitives, participles, and gerunds. A finite verb is "limited"; an infinitive is "unlimited." In John walks the action is limited to John, and to the present time; in To walk is easy the action is not limited to any subject or to any time. From this example it is clear that an infinitive is a form of a verb which is used partly like a verb, partly like a noun. The to which usually precedes it is not an essential part of it, but is its sign.

He wishes to go. (With sign.) I saw him go. (Without sign).

The infinitive has two tenses, the present and the present perfect. The present tense shows that the action is incomplete at the time of the principal verb: as, "He wishes to eat"; "He wished to eat." The present perfect tense shows that the action was complete at the time of the principal verb; as, "It is a pleasure to have finished it." The infinitive may be used as several parts of speech: 1. As a noun. It may be used in either (a) the nominative or (b) the objective case.

To help a friend is a pleasure. (Subject).

To help a friend is to give ourselves pleasure. (Subject and subjective complement).

The request to help a friend must not be lightly considered. (In apposition with a noun).

It is a pleasure to help. (Subject, it being an expletive.) She will do anything but wash dishes. (Object of the preposition).

2. As a verb. It may be used in (a) either the active or the passive voice, if the verb is transitive; (b) either the present or the present perfect tense (see sect. 89).

It may take a subject (see p. 120), and may be followed by a noun or pronoun, or by an adjective.

We believed the winner to be him. (See sect. 72.)

Did you know it to be me? The butter appears to be sweet.

Note. These infinitive clauses have the same meaning as noun clauses introduced by that.

It may take an object, if the verb is transitive.

He was urged to give money.

3. As an adjective.

We have a boat to let. (Noun modifier).

This old horse is to be shot. ( Subjective complement).

4. As an adverb.

We shall play to win. (Infinitive of purpose).

We are ready to play ball. (Modifier of the adjective).

5. Without grammatical connection with the rest of the sentence.

To tell the truth, he is no student.

Exercises

242. Justify or correct the tenses of the following infinitives:

1. He was eager to have met Edith.

2. I am glad to have seen you.

3. He hoped to come early.

243. Why are the tenses of the infinitives in the following sentences correct?

1. The money ought to have been sent before this.

2. The money ought to be sent before next week.

3. Boon Island Light was so far away that when I turned to look at anything else, and then turned to find the light again, it seemed to have sunk suddenly into the water.

244. Why are the following infinitives incorrectly used?

1. I had intended to have written you last week.

2. I should have liked very much to have gone with you.

245. In each of the following sentences, state whether the present or the present perfect infinitive of the verb in parenthesis would be correct, and give your reasons.

1. We ought (think) of the danger before going, but we didn't.

2. I meant (write) you last month.

3. I had intended (send) the package sooner.

4. I ought (tell) you what (expect); then you would not have been surprised.

5. You are fortunate (study) so long with so fine a music teacher; may you be lucky enough (find) another as good.

6. Center Pond is so large that I think its discoverers ought (call) it a lake.

7. The pond is so large that I think the people living near it ought (call) it a lake.

8. What is supposed (be) the arrangement of the solar system ?

9. How is the solar system supposed (form) ? (Use the passive voice).

10. Sebastian imagined his twin sister, Viola, (lose) at sea some time before. (Use the passive voice).

11. As she could not find the boys, she believed them (be) out fishing.