1.  We — need to 've got to can check out before 12 or the hotel will charge us for another night.

2.  When we were children, we — couldn't shouldn't weren't allowed to stay out late.

3.  I — should have must have ought to have packed some warmer clothes - I'm freezing!

4.  You — mustn't aren't supposed to don't have to drop litter here, but many people do.

5.  Some members of my family — couldn't needn't weren't able to attend our wedding. It was held abroad.

6.  I — mustn't needn't don't have to study tonight because my exams are over.

7.  We — ought to should have 'd better look in on your mother this weekend. She hasn't been well.

8.  We — didn't need to didn't have to needn't ring the bell because the door was open.

9.  You — are supposed to should ought to see a doctor about that cough.