1. If Mary saw the sight, she could tell you about that.
2. If I knew his address, I could give it to you.
3. If he had shaved more often, he would have looked a lot better.
4. If she had not been ill, she would have gone to work.
5. If it had not been raining all morning, we would have gone out.
6. If you don't keep silent, you will wake the baby up.
7. If you don't stop talking, you will not understand the lesson.
8, If you had not talked to me about my problem yesterday, I would not feel better now.