Modal verbs

A. Ability

● Can / can't / cannot / could (Present /future)
● Could / couldn't / could not (Past)

Ex.:
- She can play piano.
- They can’t study alone.


B. Possibility

● May / might / could / may not / might not / could not / couldn’t (Present/future)
● Might have / may have / could have (past)

Ex.:
- Jane might go to the party.
- Jess may win the competition.


C. Permission

● Can /can’t / may/ may not

Ex.:
- Teacher, sorry I'm late. May I come in?
- Dad, can I go to the party?


D. Certainty/ Obligation

● Must / mustn't / must not (present / future)
● Must have (past)

Ex.:
- You must obey the school's rules.
- Tomorrow you have a Maths test. You must study!


E. Advice

● Should / shouldn't (present/ future)
● Should have (past)

Ex.:
- I think you should talk to them.
- Should he go to the doctor?