1. She doesn't live in London because she doesn't know anyone there. ➡ She'd live in London if she knew anyone there.

2. I can't live in the country because I can't find a job there. ⇒ If I could find a job there, I would live in the country.

3. I don't have a spare ticket. I can't take you to the concert. ➡ If I had a spare ticket, I would take you to the concert.

4. Go right now or you'll be late for the train. If you don't go right now, you will be late for the train.

5. They don't understand the problem. They won't find a solution. ➡ If they understood the problem, they would find a solution.

6. He sits around too much. He isn't fit. If he didn't sit around so much, he would be fit.

7. Carol didn't answer the phone because she was studying. If Carol hadn't been studying, she would have answered the phone.

8. Rita is exhausted today because she didn't get any sleep last night. If Rita had gotten some sleep last night, she wouldn't be exhausted today.

9. She's very thin; perhaps that's why she feels cold so much. If she wasn't so thin, she might not feel cold so much.

10. He never polishes his shoes, so he never looks smart. If he polished his shoes, he would look smart.

11. He can't park near his office; that's why he doesn't come by car. If he could park near his office, he would come by car.

12. My house is guarded by two big dogs. That's the only reason it isn't broken into every night. ⇒ If my house wasn't guarded by two big dogs, it would be broken into every night.

13. The flats are not clearly numbered, so it is very difficult to find anyone. ➡ If the flats were clearly numbered, it would be easier to find anyone.

14. I don't know her e-mail address, so I can't tell you. If I knew her e-mail address, I would tell you.

15. She works in the evening. She has no time to play with her children.

If she didn't work in the evening, she would have time to play with her children.