1. can I help you, madam?
2. i could get you a cup of tea.
3. Jack could not see her face. She was sitting with her back to him.
4. James was an excellent tennis player. He can beat anybody.
that motorists should be tacked belts
students should work systematically
Tony should not work on this dangerous job
Ann should not miss exams
you ought to be punctual
the applicant should understand how our organization works
1. Must we sign in?
We had to sign in
We will have to sign in
2. The contractors mustn’t argue about it.
The contractors had not argue about it
The conractors will not have argue about it
3. You must arrive at the airport in time.
you had arrive at the airport in time
you will have to arrive at the airport in time
4. Motorists must drive very carefully.
motorists had drive very carefully
motorists will have to drive very carefully