1. Only when you grow up can you understand it.

2. Only if you tell me the truth, can I forgive you.

3. Only after the film started, did I realize that I'd seen it before.

4. So strange was the situation that I couldn't sleep.

5. So difficult is the test that students need three months to prepare.

6. So easy is the exercise that every student can do it easily.

7. Not only does he study well, but he also sings well.

8. Should you meet her, please call me!

9. Had you obeyed orders this disaster would not have happened.