1. THE INFINITIVE FORM Present Inf.: to work , to do
Present Continuous Inf.: to be working
Perfect Inf: to have worked
Perfect Continuous Inf.: to have been working
Present Inf. Passive: to be done
Perfect Inf. Passive: to have been done

2. USES OF THE INFINITIVE Subject of a sentence The object of a verb
To lean out of the window is dangerous
To save money now seems impossible
The object of a verb
His plan is to keep the affair secret
He wants to pay
He wants to know how to do it
She didn’t know what to do.

3. USES BE+INF.: to express commands or instructions
No one is to leave this building without the permission of the police. ( no one must leave)
He is to stay here till we return (he must stay)

4. USES He went to France to learn French They stopped to ask the way.
To express purpose
He went to France to learn French
They stopped to ask the way.
He sent Tom to the shop to buy bread

5. USES After certain adjectives I was depressing to find the house empty
It’s awful to be alone in such a place
It’s boring to do the same thing every day
It was impossible to study at home

6. The Perfect Infinitive
FORM
to have + past participle
e.g, to have worked, to have spoken

7. THE PERFECT INFINITIVE
USE WITH AUXILIARY VERBS

8. The Perfect Infinitive
Used after was/were:
The house was to have been ready today (but it isn’t)
To express an unfulfilled plan or arrangement

9. The Perfect Infinitive
With would, should, might, could
If I had seen her I should have invited her.
To form the perfect conditional

10. The Perfect Infinitive
With should and ought to:
He should have helped her.(but he didn’t)
I shouldn’t/oughtn’t to have lied to him (but I did)
To express unfulfilled obligation; or, in the negative, a foolish or wrong action

11. The Perfect Infinitive
With should/would like
He would like to have seen it (but it wasn’t possible) OR
He would have liked to see it
NO CHANGE IN MEANING
To express an unfulfilled wish

12. The Perfect Infinitive
With could
I could have made a lot of money. (but I didn’t)
To express past unused possibility

13. The Perfect Infinitive
With may/might/could
He may/might have left= It is possible that he (has)left.
You might/could have been killed!
He could have phoned her. [perhaps he (has)phoned]
Speculations about past actions

14. The Perfect Infinitive
with might/could
He might/could have told me = I am annoyed that he didn’t tell me
To indicate that the speaker feels upset or indignant at the non-performance of an action

15. The Perfect Infinitive
With can’t/couldn’t
He can’t/couldn’t have moved the piano himself
We knew he couldn’t have paid for it, because he had no money
To express a negative deduction

16. The Perfect Infinitive
with must
He must have come this way; here are his footprints
To express affirmative deduction

17. The Perfect Infinitive
With needn’t
You needn’t have hurried.Now we are too early.
You needn’t have cooked it. We could have eaten it raw
To express an unnecessary past action

18. THE PERFECT INFINITIVE
WITH CERTAIN OTHER VERBS

19. THE PERFECT INFINITIVE
He seems to have been…= It seems that he is
He seemed to have been…= It seemed that he had been..
I happened to have driven that kind of car before=It happened that I had driven that…
He pretended to have read the book. =…
With appear, happen, pretend, seem

20. THE PERFECT INFINITIVE
He is understood to have left the country.=…
He is believed to have been waiting for a message =People believed he was waiting for a message
You are supposed to have been working= You should have been working
With the following verbs in the passive voice: acknowledge
believe
consider, find, know, report, say, suppose, think, understand