The infinitive is a verb-form that has some of the properties of a noun. Its two-sided character comes out clearly when it is used as the subject of a sentence.
1. To hope is our only resource.
2. To flatter is not my custom.
3. To sleep was an impossibility.
4. To surrender seemed disgraceful.
5. To choose wisely was my greatest difficulty.
6. To scale the wall was the work of a moment.
Each of these infinitives (to hope, to flatter, etc.) is a noun, for each is the simple subject of a sentence. Besides, an ordinary noun may be substituted for each infinitive with no change in meaning such as…..
1. Hope is our only resource.
1. Flattery is not my custom.
2. Sleep was an impossibility.
But each of these infinitives is also a verb…..for (1) it expresses action (2) it may be modified by an adverb such as in No. 5 (3) it takes an object if it is transitive as in No. 6.
An infinitive (as the EXAMPLES show) has regularly no subject and therefore lacks both number and person. Hence it is not bound by the general rule for the agreement of a verb with its subject. From this fact it derives its name infinitive which means unrestricted or free from limitations.
The infinitive is a verb-form which partakes of the nature of a noun. It expresses action or state in the simplest possible way without person or number.
It is commonly preceded by the preposition TO which is called the sign of the infinitive.
TO is not, in strictness, a part of the infinitive, but it may be so regarded for convenience, since the infinitive, in most of its uses, is preceded by TO.
Note : TO sometimes stands for an infinitive in careless speech such as….. You may go if you wish to. (That is….if you wish to go). Such expressions are to be avoided. It is better to say….You may go if you wish.
The infinitive often lacks to, especially in verb-phrases with the auxiliaries will, shall, may, can, must, might, could, would, should, do, did.
The infinitive has two tenses……the present and the perfect.
1. The present infinitive is the verb in its simplest form, usually preceded by TO such as…..to live, to teach, to bind, to strike.
2. The perfect infinitive is made by prefixing the infinitive of the auxiliary verb HAVE to the past participle such as……to have lived, to have taught, to have bound, to have struck.
An infinitive may be modified by an adverb - an adverbial phrase or an adverbial clause.
1. To write legibly is a valuable accomplishment.
2. It would be useless to search longer.
3. They allowed him to go in peace. [Adverbial phrase.]
4. To dive among those weeds would be folly.
5. Theodore promises to come when I send for him. [Adverbial clause.]
No modifier should be inserted between TO and the infinitive.
1. I beg you to inquire carefully into this matter. [Not: to carefully inquire.]
2. Mr. Harris moved to postpone the question indefinitely. [Not: to indefinitely postpone.]
3. I expect always to be poor. [Not: to always be poor.]
Note : Careless writers pay slight attention to this rule, and some good writers and speakers defy it, hoping to break it down. But it is unquestionably still in accord with the best usage.
The infinitive may take an object if its meaning allows.
1. I long to visit Italy.
2. My mother feared to enter the house.
3. To launch a boat was impossible.
4. To grant your request is a pleasure.
5. To give him money is useless. [Money is the direct object of to give, and him the indirect object.]
The infinitive is used in a variety of constructions (1) as a noun (2) as an adjective modifier or adverbial modifier (3) in the so-called infinitive clause.