| Can is used to express the ability to do something: |
:: She can speak English very well.
:: Can Janet play the piano? No, she can't.
:: I can't drive a car. |
| Can also expresses the possibility to do something: |
:: We can go to the concert tonight.
:: We can play tennis this afternoon.
|
| May is used to express probability: |
:: We may go to the park after school.
:: I may play football with my friends on Sunday.
|
| May is also used for permissions: |
:: You may stay here.
:: May I borrow your pen? |
| May is more formal. In informal spoken English we sometimes use can to request permission ("Can I open the window?"). |
| We use might as a past form of may and to express probability (= it's very unlikely): |
:: She said that she might move in the new house.
:: We might go to the Austria next year.
|
| Could is used as a past form of can: |
:: Could you finish your homework last night?
|
| We also use could to ask for permission: |
:: Could I borrow your pen, please?
:: Could I go out?
|
| Must is used for strong obligation, recommendation, and conclusion: |
:: He must clean his room.
:: I must write an essay.
:: You must see this film.
:: John must be in London now.
|
| Will is used for asking or ordering somebody to do something: |
:: Will you help me, please.
:: You'll wash the dishes now!
|
| Will is also used to express willingness and intention: |
:: I'll help you, I promise.
:: I will call you as soon as I arrive.
|
| Will is used for talking about or predicting the future: |
:: I'll tell you what I think about them.
:: You'll be there in time if you hurry.
:: I'm sure you'll be fine!
|
| Would is used to make polite request and to give hypothetical advice: |
:: Would you pass me the salt, please.
:: If I were you, I would go to the Unated States.
:: I would not (wouldn't) do that. |
| We use shall in questions to make offers or suggestions: |
:: Shall I close the door?
:: Shall we go to the theatre tonight? |
| Should is used to give advise: |
:: You should do exercises every day.
:: You should not (shouldn't) smoke. |
Modal verbs in English (also called modal auxiliary verbs) are used to express ability, possiblity, probability, certainty, permission, prohibition, obligation, wish, etc.
Many modal verbs cannot be used in all of the English tenses. That's why we need to know the substitutes to these modal verbs: