Give the correct form of the verbs:
1. My friend promised (return) __
to return______ the book very soon.
2. Most people enjoy (write) ____
writting_______ letters to their friends.
3. Tom avoids (study) ____
studying____ his lessons as long as possible.
4. David finished (write) ______
writting_____ the report about four o’clock.
5. How soon do you expect (leave) _____
to leave___________ for South America?
6. Have you considered (try) ______
trying________ something different?
7. Are you going to suggest (travel) _______
traveling_________ by plane or not?
8. I can’t stand (listen) _______
listening_____ to his complaints any longer.
9. My father is retired. He stops (working) _______
working_________ now.
10. We had the water pipe (repair) _____
need to be repaired______ by the plumber.
11. Mrs. Baker got them (keep) _______
to keep_________ her house.
12. She wanted the letter (send) ______
to be sent______ at once.
13. It will make difference (try) ____
in trying_____ at this time.
14. My children have to (learn) ______
learn_____ the lesson now.
15. I look forward to (hear) _____
hearing_____ from you.[/quote]