Infinitive Worksheet

The forms and functions of the Infinitive: free exercises and answers to check your result.

Exercise  1
Define the forms of the Infinitive (Passive or Active; Indefinite, Continuous, Perfect or Perfect Continuous) in the following sentences.

1. I want to see your design.
2. It can be done.
3. The mistake must be found.
4. We knew him to be working in the room.
5. They are likely to be being served now.
6. I remember to have seen her somewhere.
7. We thought the mistake to have been found.
8. He must have been working all night.
9. She appeared to have been leading a very busy life before.
10. It’s nice to be sitting here with you.
11. It’s good to have finished work for the day.
12. I’m sorry not to have come on Friday.
13. I appear to have made a small mistake.
14. I didn’t expect to be invited.
15. There is a lot of work to do.
16. There is a lot of work to be done.

The Infinitive

The Forms of the Infinitive

	Active	Passive
Indefinite	to teach	to be taught
Continuous	to be teaching	to be being taught
Perfect	to have taught	to have been taught
Perfect Continuous	to have been teaching	---

The Indefinite Infinitive expresses an action simultaneous with that expressed by the finite verb.
E.g.: I shall be glad to see him.

The Continuous Infinitive denotes an action in progress simultaneous with that expressed by the finite verb.
E.g.: He seemed to be waiting for us.

The Perfect Infinitive denotes an action prior to that expressed by the finite verb.
E.g.: I am sorry to have troubled you.

The Perfect Continuous Infinitive denotes an action which lasted a certain time before the action of the finite verb.
E.g.: He proved to have been teaching English for ten years.

The Active Infinitive denotes that the subject is the doer of the action.
The Passive Infinitive denotes that the subject is acted upon.
E.g.: The man came to teach us English.
         The man came to be taught English.

Should and Ought to

Modal verbs: Should and Ought

There is hardly any difference in meaning between should and ought. Both express duty, obligation, advice. It must be remembered that ought is always followed by to + infinitive.

Patterns. Read and memorize!

1. John should study English hard. 
2. John should read English books loudly. 
3. John should work on his pronunciation. 
4. John should write dictations regularly. 
5. John ought to practise oral drills.
6. John ought to drill the patterns.
7. John ought to recite English poems. 
8. John ought to listen to good records.

Modal Verb May

The Forms, Meanings and Use of the Modal Verb MAY (MIGHT).

May and might are modal auxiliary verb, like for example must , can  and ought. These verbs have no infinitives or participles (to may, mighted, maying do not exist), question and negatives are made without do (may I?, not Do I may?). Like other modal verbs, 'may' has no –s on the third person singular (he may, not he mays); 'may' and 'might' are followed by infinitives without to.  

Patterns. Read and memorize! 

Affirmative	Interrogative	Negative
I may attend lectures at the University.	May I attend lectures at the University?	I may not attend lectures at the University.
He may attend lectures at the University.	May he attend lectures at the University?	He may not attend lectures at the University.
She may attend lectures at the University.	May she attend lectures at the University?	She may not attend lectures at the University.
It may go.	May it go?	It may not go.
We may attend lectures at the University.	May we attend lectures at the University?	We may not attend lectures at the University.
You may attend lectures at the University.	May you attend lectures at the University?	You may not attend lectures at the University.
They may attend lectures at the University.	May they attend lectures at the University?	They may not attend lectures at the University.

Note 1: - The modal verb 'may' has two forms – may in the present and might in the past. The missing tense is supplied by the future of to be allowed to.
E. g. : I shall be allowed to attend lectures at the University.
          He was allowed to come later.

Note 2: - Contracted negative forms exist: mightn’t is common, but mayn’t is very unusual.


► Might does not normally have a past sense, but it can be used as the past tense of 'may' in 'indirect speech' to report the giving of permission.

• 'What are you doing here?' – 'The manager said that I might look round.'
• He said that we might take his car. 

Modal Verbs: Can

The Forms, Meanings and Use of the Modal Verb CAN (COULD).

Can and could are modal auxiliary verb, like for example must, may and should. Like other modal verbs, 'can' has no –s on the third person singular (he can, not he cans); questions and negatives are made without do (Can I?, Could I? not Do I can?, Did I could?); these verbs are followed by the infinitive without to (e. g.: I can do it.). 'Can' and 'could' have no infinitive or participles (to can, canning do not exist).

Patterns. Read and memorize! 

Affirmative	Interrogative	Negative
I can swim.	Can I swim?	I cannot swim.
He can swim.	Can he swim?	He cannot swim.
She can swim.	Can she swim?	She cannot swim.
It can swim.	Can it swim?	It cannot swim.
We can swim.	Can we swim?	We cannot swim.
You can swim.	Can you swim?	You cannot swim.
They can swim.	Can they swim?	They cannot swim.

Note 1: - the modal verb 'can' has only two forms – can in the present and could in the past. The missing tense is supplied by the future of to be able.
E. g. : I shall be able to prepare for my exams.

Note 2: - There are contracted negative form can’t, couldn’t.
E. g.: I can’t understand.

Be careful about the pronunciation of 'can’t': in British English it has a quite different vowel from 'can'.
Can [kᴂnt]; can’t [kɑːnt] (GB), [kᴂnt] (US).

Modal Verbs: Must

The Forms, Meanings and Use of the Modal Verb MUST.

Must is a modal auxiliary verb. 'Must' has no infinitive or participles. It  has only one tense form in the present. Like other modal verbs, 'must' has no –s on the third person singular (he must, not he musts); questions and negatives are made without do (Must I?, not Do I must?); 'must' is followed by the infinitive without to (e. g.: I must do it).

Patterns. Read and memorize! 

Affirmative	Interrogative	Negative
I must do it now.	Must I do it now?	I must not do it now.
He must do it now.	Must he do it now?	He must not do it now.
She must do it now.	Must she do it now?	She must not do it now.
It must do it now.	Must it do it now?	It must not do it now.
We must do it now.	Must we do it now?	We must not do it now.
You must do it now.	Must you do it now?	You must not do it now.
They must do it now.	Must they do it now?	They must not do it now.

Note 1: - The missing tenses are supplied by the past and the future tenses of to have.
E. g. : I had to meet him at the station.
          I shall have to meet him at the station.

Note 2: - There is a contracted negative form mustn’t [mʌsnt].
E. g.: He mustn’t find out what’s happening.