7. She walked to the meeting. She was late.
→ If she hadn't walked to the meeting, she wouldn't have been late.
8. Unless you promise to return back, I won't lend you.
→ If you promise to return back, I will lend you.
9. We put off our trip because the weather was terrible.
→ If the weather hadn't been terrible, we wouldn't have put off our trip.
10. Sally doesn't know what she has to do for homework because she was absent from school on Friday.
→ If Sally hadn't been absent from school on Friday, she would know what she has to do for homework.
11. If you do not like this one, I'll bring you another.
→ Unless you like this one, I'll bring you another.
12. Martin failed his driving test last week because he was very nervous.
→ But for his nervousness, Martin wouldn't have failed his driving test last week.
13. He will pay me tonight; I will have enough money to buy a car.
→ If he pays me tonight, I will have enough money to buy a car.
14. Leave me alone or I'll call the police.
→ If you don't leave me alone, I'll call the police.
15. If you arrive at the office earlier than I do, please turn on the air-conditioner.
→ Should you arrive at the office earlier than I do, please turn on the air-conditioner.
16. He died so young; otherwise, he would be a famous musician by now.
→ If he hadn't died so young, he would be a famous musician by now.