1. If you don't keep silent, you'll wake the baby up.
2. If you stop talking, you will understand the lesson.
3. If I knew here phone number, I would ring her up.
4. If I knew the answer, I could tell you.
5. If we had had a map, we wouldn't have got lost.
6. If Susan hadn't eaten four cream cakes, she wouldn't have felt sick.
7. If the patient hadn't followed this treatment, he would have died.
8. If he hadn't been late every day, he wouldn't have lost his job.
9. If Peter didn't eat so many chips, he wouldn't be fat.
10. If Robert hadn't started smoking cigarettes, he wouldn't have got a bad cough.