Replace can (could)by its substitute be able to in the correct tense, adding the
words in brackets.

1. I can give you a book for a couple of days (after I have read it myself).
2. I couldn’t understand the rule (before the teacher explained it to me).
3. You can earn your living (when you learn some trade).
4. She told me she could swim (since she was a child).
5. I think I can speak English quite well (in a few months).
6. He can play the piano (for many years).
7. My mother could make her own clothes (when she was a girl of fifteen).
8. She can’t speak French well (not yet).

 9. I don’t believe computers can think better than we do (in a few years).
10. We can travel a lot (one day).