Present, preterit :
can, could (possibilité, capacité)
may, might (probabilité, permission)
must, ought to (devoir, obligation)
shall, should (devoir, obligation)
have to (obligation)
will, would (futur)
* * * * * * * * * *
Examples:
You can do it.
She can't come.
She may come tomorrow.
May I close the door?
The child must do his homework.
I don't have to go to school.
- Subject + modal verb + verb + object
Plus de détails : e-anglais