I can/must go to the mall beacuse my mum let me.
can
Geography starts at 8. We mustn't/ don't have to be late.
mustn't
May/should I borrow your pen? I have lost mine.
May
Shall/ must we go to the cinema?
shall
I will come to the mall with you. I really might/ need to buy a new notebook
need to
She didn't tell me anything but she need to/ might come to the meeting
might
My doctor said that I have to/must eat more vitamis.
have to
It is free. You don't have to/ must pay for it.
don't have to
They said that it might/must snow today.
might
I want to be the best runner so I have to/ must exercise a lot
must
You don't look good. You should/ have to go to the doctor
Should
You don't need to/ mustn't drive when the light is red.
mustn't