1. They can not do this work themselves
2. You may take my dictionary.
3. You don't look well, you should consult the doctor.
4. Why would I give you my money?
5. She can not speak any foreign language.
6. He ought to help them, they need his help.
7. Can you tell me the time?
8. May I go with you? No, you may not.
9. Your daughter needn't have told about it.
10. In winter we can often skate.
11. You must not miss your classes.
12. Could you play the piano before?