1..My brother doesn't buy that car because he doesn't have enough money.

If ..........My brother had enough money,he would buy that car .......................

2. We don't go out beacuse it rains

If.............it didn't rain,we would go out ....................

3.I don't know his address, so I can't contact him.

If........................I knew his address, I could contact him................

4.It's too cold so we can't go swimming.

If..................It weren't too cold , we could go swimming.............

5.The exercises are very difficult so I can't finish in fiffteen minutes.

If.................The exercises weren't very difficult , I could finish in fiffteen minutes......................

6.She can't go to the meeting bacause she is busy

If..............she weren't busy,She could go to the meeting.......................

7.because I don't meet her, I don't give her your letter.

If................. I met her, I would give her your letter......................

8.They are too slow, they can't win the mach

If...........They weren't too slow, they could win the mach.........

9.She is too weak, she can't take any exercise.

If...................She weren't too weak, she could take any exercise.................................

10.People don't understand him bacause he doens't speak clearly

If.....................he  spoke clearly,People would understand him.............................-