The Grammaring Guide to English Grammar with Exercises

The forms of the infinitive

An infinitive can be a to-infinitive or a bare infinitive (without to). There is no difference in meaning between them; some structures require a to-infinitive, while others call for a bare infinitive:

I ought

to call

them.

(

to

-infinitive)

I had better

call

them.

(bare infinitive)

In the negative, not usually comes before the infinitive:

I ought

not to call

them.

I had better

not call

them.

In some cases, the verb in the main clause is negative, not the infinitive:

I

want

to call them.

I

don't want

to call them.

As the infinitive has no tense, it does not in itself indicate the time of the action that it refers to. However, it can have aspect, which shows the temporal relationship between the action expressed by the infinitive and the time of the preceding verb. There are four types of infinitive, each of which has an active and passive form:

Active

Passive

Simple infinitive

(to) write

(to) be written

Continuous infinitive

(to) be writing

(to) be being written

Perfect infinitive

(to) have written

(to) have been written

Perfect continuous infinitive

(to) have been writing

(to) have been being written

Simple infinitive

The simple infinitive refers to the same time as that of the preceding verb:

I

was

glad

to see

her.

He

must

be

very happy.

I

'll

arrange

a meeting with the manager.

My son's football coach

is said

to be

very strict.

Continuous infinitive

The continuous infinitive refers to the same time as that of the preceding verb and expresses an action in progress or happening over a period of time:

I

'm

glad

to be sitting

here.

You

must

be joking

.

This time next week, I

'll

be lying

on the beach in Croatia.

Vincent

was reported

to be staying

in Paris at that time.

Perfect infinitive

The perfect infinitive refers to a time before that of the preceding verb:

I

'm

glad

to have studied

at that school.

They

must

have forgotten

about the deadline.

By next week, they

'll

have finished

painting the rooms.

Lucy

was assumed

to have left

the day before.

Perfect continuous infinitive

The perfect continuous infinitive refers to a time before that of the preceding verb and expresses an action in progress or happening over a period of time:

I

'm

glad

to have been living

in Barcelona for the last ten years.

He

must

have been waiting

for ages.

Soon, he

'll

have been running

for four hours.

The organisers

were thought

to have been preparing

for days.

Passive infinitives

Passive forms are also possible:

Your composition

has

to be typed

.

(passive simple infinitive)

The spy's phone

was believed

to be being tapped

.

(passive continuous infinitive, rarely used)

This sonnet

must

have been written

by Shakespeare.

(passive perfect infinitive)

The picture

is believed

to have been being painted

for years.

(passive perfect continuous infinitive, rarely used)

Quotes:

Live as you will wish to have lived when you are dying. - Christian Furchtegott Gellert

To be wronged is nothing unless you continue to remember it. - Confucius

Success usually comes to those who are too busy to be looking for it. - Henry David Thoreau

Nothing in life is to be feared. It is only to be understood. - Marie Curie

Some things have to be believed to be seen. - Ralph Hodgson

Related topics:

The continuous aspect

The perfect aspect

The perfect continuous aspect

Types of modals

Form: passive voice

Appendix: irregular verb forms