Modal verbs

modal meaning
can Ability- Example: I can swim.
Permission (informal) – Example: You can go out.;
Offers – Example: Can I help you?
Requests– Example: Can you open the door, please?
Theoretical possibility – Example:It can be really cold in May.
could Past ability – Example: I could swim when I was five.
Request (polite)- Example: Could you open the window, please?
Suggestion – Example: We could go shopping together.
Possibility– Example: He could come to the party.
can’t Lack of ability – Example: I can’t ski.
Prohibition – Example: You can’t smoke here.
must Obligation (we feel it is necessary to do something) –
Example: I must get up early on Sunday to finish the project.
Strong advice – Example: You must see this.
mustn’t Prohibition
Example: You mustn’t take photos in the museum.
have to Obligation coming from outside (rule, regulation etc) Example: All the students at our school have to wear uniforms.
Don’t have to Lack of necessity – Example: I don’t have to get up early at weekends. (but I can do it, it is not prohibited)
Should/ ought to Advice – Example: You should/ought to take vitamin pills.
may Possibility (50%) –
Example: We may go to the Bahamas next year.
Permission (formal) – Example: You may see the manager now.
Request – Example: May I talk to the headmaster, please?
might Possibility (30%) – Example: We might visit the Eiffel Tower next summer.
Permission (formal) – Example: You might enter now.
Request Example: Might I leave early today?
shall Offer, suggestion – Example: Shall I make you a sandwich? Shall we go to the cinema tonight?

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