1. I can/could speak English but I can't write it very well.
2. She can’t/needn’t spend 3 weeks in Rome, she has to come back to work.
3. You mustn’t/shouldn’t park your car on double yellow lines.
4. You shouldn’t/mustn’t be so rude with Mary, she is very sensitive.
5. You should/must obey the laws, or you will get in jail.
6. Should/May I borrow your pen, please?
7. You needn’t/have to buy any cat food. We’ve got plenty.
8. I think you ought to/might take your dog to a vet.
9. May/must I call you next week, please?
10. It might/should rain tomorrow. You should take an umbrella with you.