modal verbs

I can skate really well.

CAN is used to show

• ability

• asking for permission

• deduction

I could read when I was 4 years old.

COULD refers to

• possibility

• past hability

• invitation

I could't go to the cinema because there was a blackout.

COULN'T expresses

• past inability

• impossibility

• prohibition

May I go out, miss?

MAY is used to

• make an invitation

• make a deduction

• asking for permission

You should do more excercise to keep fit.

Should is used to

• express ability

• make an invitation

• give advice

We must save some more money.

MUST is expressing

• a wish

• a necessity

• a prohibition

She must be seeply. She hasn't slept all night.

MUST is used to express

• deduction

• ability

• invitation

Would you do me a favour?

WOULD is used to

• make a polite request

• make a suggestion

• make a deduction

Would you like to come to the cinema with us?

WOULD is used to

• express advice

• make an invitation

• make a deduction

You MUSTN'T run in the corridors.

MUSTN'T is used to

• express prohibition

• to express obligation

• to express impossibility