Modal verbs

Ability: can/can’t, could/couldn’t• CAN/CAN’T for things we are able to do

generally or at the moment

She can speak Japanese (she is able to speak Japanese)

I can see the moon I am able to see the moon now)

• COULD/COULDN’T for past abilities• WILL BE ABLE TO for future abilities

Can/Could I? May I? Could you?• Can/Could I? May I? to ask permission. Could/May I?

more formalCould I have two tickets please?• Can/Could to give permissionYou can go out tonight• For something allowed in general rather than for a

particular person, we use CANPeople can drive on the roads when they are eighteen• BUT in official notices MAY

Bags may be left here• Can/Could/Would you? (not MAY YOU) to aske

someone to do somethingCould you close the window?

Must/Have to

MUSTWhen the speaker

thinks it is necessary/important to do an action

You must clean your room

HAVE TOWhen something is

compulsory

In England you have to wear a uniform to go to school

Mustn't/Don't have to

MUSTN'TTo say that smth is

against the rules/laws

You mustn't smoke on buses (it's against the rules)

DON'T HAVE TOTo say that smth is

unnecessary

You don't have to learn Latin at school (you're not obliged to do that)

Must/can't/may/might/could

• CERTAINTY → MUSTThe Greens have two houses and two cars.

They must earn a lot of money• IMPOSSIBILITY → CAN'TMark studied a lot for his exams, but he got

poor marks; he can't be very clever• POSSIBILITY → MAY MIGHT COULD1) She may be in the garden (= perhaps she

is in the garden2)

Should/Shouldn't

SHOULD

To say that smth is a good thing for us to do

You should do your homework

To give positive adviceYou should eat more fruit (=

It's a good idea)You must eat more fruit – said

the doctor (= it's very important)

SHOULDN'TTo say that smth is a bad thing

for us to doYou shouldn't stay in the sun

all day

To give negative adviceYou shouldn't drive so fast (=

it's dangerous)

Should/ought to

Ought to is different from should.

• Ought to is generally used to talk about duties of law

A: I saw a robbery. What should I do?B: You ought to report to the police (= it is

a person 's duty to report it)

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