1. Only after several months did we begin to see the symptoms of the disease
2. Only later were the facts all made public
3. Only by studying hard can you pass this exam
4. Only when you grow up can you understand
5. Only if you tell me the truth can I forgive you
6. Only after the film started did I realize that I'd seen it before
7. Only then did I understand the problem
8. Only by working hard will we be able to accomplish this great task
9. Only by operating immediately can you save your eyesight
10. Only when I saw the photograph did I know that he was your brother
11. Not only does he study well but he also sings well
12. Barely was the judge taken when the trial proceedings began
13. Should you meet her, please call me! 
14. Had you obeyed orders, this disaster would not have happened
15. Had I realized what would happen, I wouldn't have accepted the job
16. Such was the response to our appeal that we has to take on more staff
17. Not only did Harry break his leg but he also injured his shoulder
18. Were the government to raise interest rates, they would lose the election
19. Should you do happen to see Helen, could you ask her to call me??
20. Had I realized what would happen, I wouldn't have accepted the job
 Form: 
- đảo ngữ only: only+then/by V -ing/ after+time+trợ động từ+...
- đảo ngữ not only: not only+TĐT+N+but+N+also+...
- đảo ngữ câu đk: Should+S+V //  Were+S+to-V/adj// Had+S+V-pp