Grammar: Modals

Modal verbs

The modal verbs include can, must, may, might, will, would, should. They are used with other verbs to express ability, obligation, possibility, and so on. Below is a list showing the most useful modals and their most common meanings:

Modal	Meaning	Example
can	to express ability	I can speak a little Russian.
can	to request permission	Can I open the window?
may	to express possibility	I may be home late.
may	to request permission	May I sit down, please?
must	to express obligation	I must go now.
must	to express strong belief	She must be over 90 years old.
should	to give advice	You should stop smoking.
would	to request or offer	Would you like a cup of tea?
would	in if-sentences	If I were you, I would say sorry.

Modal verbs are unlike other verbs. They do not change their form (spelling) and they have no infinitive or participle (past/present). The modals must and can need substitute verbs to express obligation or ability in the different tenses. Here are some examples:

Past simple	Sorry I'm late. I had to finish my math test.
Present perfect	She's had to return to Korea at short notice.
Future	You'll have to work hard if you want to pass the exams.
Infinitive	I don't want to have to go.

Past simple	I couldn't/wasn't able to walk until I was 3 years old.
Present perfect	I haven't been able to solve this problem. Can you help?
Future	I'm not sure if I will be able to come to your party.
Infinitive	I would love to be able to play the piano.

Modals are auxiliary verbs. They do not need an additional auxiliary in negatives or questions. For example: Must I come? (Do I must come?), or: He shouldn't smoke (He doesn't should smoke).

Important: The explanations and examples on this page are just an introduction to this extensive and complex area of English grammar. Students of English who want to learn more should consult a good reference work, such as Swan's Practical English Usage.

Do a quiz on modal verbs.

http://www.xtec.cat/~ogodoy/sac/rephrasing/modalsex1.htm

Rephrasing modals 1

Rewrite the following sentences so that they have the same meaning as the original. Use modal verbs. 

1. Taking my computer without saying a word to me was the wrong thing to do.

You………………..

2. It’s necessary to wear uniform to work with this firm.

You……………………………………

3. Perhaps Jane is in the garden now.

Jane……………………………………

4. It is idiot from her to take so much fat.

She……………………………………..

5. It was obligatory for them to knock at the door before entering.

They ……………………………….

6. He is definitely stressed.

He ………………………..

7. I don’t let my son stay out after 11.

My son ……………………….

8. It is good for us to practice more exercise.

We…………………………………………..

9. There’s a tiny opportunity for her to get that job.

She …………………………………

10. It wasn’t a good idea to leave the mobile on the table while she wasn’t looking.

She ……………………………………

11. We’re sure they will win the next election.

They …………………………..

12. It isn’t obligatory to knock at the door before entering.

You ………………..

13. It is forbidden to play any loud music after 12 at night.

You………………………………

14. It’s possible their parents lent them the money for their new house.

Their parents ………………………………..

15. Laws don’t allow young people to drive before they are 18.

Young people ………………………………………….

16. I’m sure that isn’t Joe; he’s much taller.

That …………………………………………………….

KEY

1. You shouldn’t have taken my computer.
2. You must wear a uniform to work with this firm.
3. Jane may/might be in the garden now.
4. She shouldn’t take so much fat.
5. They must knock at the door before entering.
6. He must be stressed.
7. My son mustn’t stay out after 11.
8. We should(ought to practice more exercise.
9. She might get the job.
10. She shouldn’t have left the mobile on the table while she wasn’t looking.
11. They will/must win the next election.
12. You don’t have to/needn´t knock at the door before entering.
13. You mustn’t/can´t play any loud music after 12 at night.
14. Their parents may have lent them the money for their new house.
15. Young people mustn’t/can´t drive before they are 18.
16. That can’t be Joe; he’s much taller.