**EX1:**
1. won't let
2. don't go
3. were, would accept
4. won
5. will you do, don't come
6. is, will go
**EX2:**
7. will have
8. had fed
9. will have
10. looked
11. will happen
12. press
13. had had
14. will you stay
15. swim
16. tell
**EX3:**
1. If you think positive, you will feel better than ever.
2. If today wasn't very cold, we could go for a walk in the park.
3. If you don't have money, you can't go shopping.
4. If you put too much salt in the soup, it will get too salty to eat.
5. If people cared much about the environment, they wouldn't keep making it worse.
6. If he took some exercises, he wouldn't be so unhealthy.
7. If I had the right change, we could get the ticket.
8. If you don't study hard, you won't pass the exam.
9. If you are impatient, you will make mistakes.
10. If they weren't poor, they could help us.
**EX4:**
1. If he has enough time, he will help me.
2. If she takes any exercise, she won't be overweight.
3. If he has a bicycle, he won't go to class late.
4. If I were good at English, I could do homework.
5. If it didn't rain, we would go because we would enjoy the weather.
6. If John didn't eat so many chips, he wouldn't be fat.
7. Unless you leave alone, I'll call the teacher.
8. If she didn't sit around too much, she would be fit.