Modal Verbs (Simple Forms)

Modal	Meaning	Example
Can Can’t	- to express ability - to request permission - to give and deny permission - to express an option - To express certainty (1%)	I can speak a little Russian. Can I open the window? Yes, you can. No, you can’t You can choose any of them. He can’t be his brother.
could	- to express ability in the past - To ask for permission (polite/formal) - To make a suggestion - To express little possibility	She could speak at the age of 2. Could I borrow your car? We could go to the cinema. He could be his brother…
May/might May	- to express possibility - to request permission (formal)	I may / might be home late. May I come in?
Will	- to express predictions (future) - to express decisions (made now) - to express offers - to make a request - to make a promise	I think you’ll be happy. Ok. I’ll phone him. Don’t worry! I’ll help you do it. Will you pay for this, please? I’ll go to the match!
Shall	- to express offers - to suggest something	Shall I help you? Shall we stay at home?
Must	- to express obligation (speaker’s orders) - to express strong recommendation - To express certainty   (99%)	I must go now. He must study it.  You must read it. It’s very good. He must live in this house.
Mustn’t	- to express prohibition	He mustn’t come to my house.
should	- to give advice	You should stop smoking.
Needn’t = Don’t/doesn’t have to	- To express no obligation, no necessity - to express an option	She needn’t write it. She doesn’t have to write it.  They don’t have to write it.
would	- to invite /offer	Would you like a cup of tea?

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

                                                         MUST

Past simple	Sorry I'm late. I had to finish my math test.
Present perfect	She has had to return home 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.

                                                          CAN

Past simple	I couldn't/wasn't able to walk until I was 3 years old. (ability) They weren’t allowed to get into the club. (permission)
Present perfect	I haven't been able to solve this problem. Can you help me? (ability)) We haven’t been allowed to speak at the meeting.  (permission)
Future	I'm not sure if I will be able to come to your party. (ability) I’m not sure if I will be allowed to stay out late. (permission)
Infinitive	I would love to be able to play the piano. (ability) I don’t want to be allowed to smoke at home. (permission)

Exercises