Infinitive

Infinitives are forms like (to) write and (to) read. Infinitives are generally used with the marker to. Note that this to is not a preposition; after the preposition to we use –ing forms.

• I would like to meet the manager.
• Is there anything to eat?
• The main thing is to stay calm.

Negative forms

Negative Infinitives are normally formed by putting not before the infinitive.

• I decided to invite them. (affirmative)
• I decided not to invite them. (negative )
• You were silly not to have locked the car. (NOT You were silly to not have locked the car.)

Perfect infinitive

The perfect infinitive is the traditional label for the structure to + have + past participle of a verb.

In the sentence I would like to have met him, the perfect infinitive is to have met.

Perfect infinitives can have the same kind of meaning as perfect tenses or past tenses.

• It is nice to have finished work. (= It is nice that I have finished work.)

We often use perfect infinitives to talk about unreal past events: things that did not happen, or that may not have happened.

• I meant to have telephoned, but I forgot.

Split infinitive

The structure in which an adverb comes between to and the infinitive verb form.

Consider the sentence She decided to never touch another cigarette.

Here the sequence to never touch is an example of what is called a split infinitive.

Another example is given below.

• I wish to really understand his motive.

Some people think that it is wrong to split an infinitive like this. But this view is wrong: the infinitive is a single word; the particle to is not part of the infinitive or part of the verb at all.