=>
1. If he had been old enough, he could ride a motorcycle.
2. If she weren't lazy, she wouldn't fail the exam.
3. If he didn't work very hard, he wouldn't get sick.
4. If the weather hadn't been bad, we could have gone to the beach.
5. If you don't keep quiet, you will be punished.
6. Unless I do my homework, my teacher will be sad.
7. If you had listened to me yesterday, you wouldn't feel tired now.
8. If we had much money, we could buy a new house.
9. If he hadn't driven his bike carelessly, he wouldn't have had an accident.
10. Unless he stayed up late last night, he would be better.
