- If we hadn't taken a wrong turning back there, we wouldn't be / have been in this mess now.
- Should / Would you need any further assistance, please don't hesitate to ask.
- Had they not / Hadn't they warned people in time, a lot more lives could have been lost.
- If you worked / had worked last weekend when the boss asked you, then you wouldn't have to work this weekend.
- Were all the members of staff to attend the conference, would the hotel have / have had enough rooms for everyone?
- Had the government acted sooner, the general public wouldn't be worrying / have worried so much about the current situation.
- Tom Cruise wouldn't be the star he is today had he not / should he not have made a good impression in his early films.
- Weren't we / Were we not to build more roads, the traffic system would collapse by 2020.
- It would be hard enough to pass the exam tomorrow even if you went / had gone to all the lectures this year.
- You can contact the hotel manager on extension 142 should / could you need to.
- Shouldn't you / Should you not receive confirmation of your flight by e-mail, please click the link below.
- I would have asked the person for ID before I let him in, if I were / have been you.
3. Had they not
4. had worked
6. be worrying
7. had he not
8. Were we not
9. had gone
11. Should you not