14. He can’t go out because he has to study for his exam.
=> If…he had to study for his exam, he would go out………………………………………………..
15. She is lazy so she can’t pass the exam.
If……she was not lazy , she could pass the exam……………………………………………………
16. I didn’t eat lunch, I feel hungry now.
=> If I…had eaten lunch , i wouldn't feel hungry now………..………………………………….
17. I only come if they invite me.
=> unless……they invite me . i will come………………………………………….
18. Leave me alone or I’ll call the police.

=>Unless…you don't leave me alone, i will call the police………………………………………………………

19. If you arrive at the office earlier than I do, please turn on the air-conditioner.

=> Should……………………………………….​

20. The children don’t go to school in the snowy weather.

=> If it wasn't  snow ,………………The children would  go to school……………………

21. He died so young; otherwise, he would be a famous musician by now.

=>Had ……………………………………………​

22. You must tell me the whole truth or I won’t help you.

=> Unless…you tell me the whole truth, ………I won’t help you.………………………………………………………​

23. The car breaks down so often because you don’t take good care of it.

=> Were I…………………………………………………………………………

Queston 5: Put the verbs in brackets into the correct form:

24. If I see him , I __will give___ (give ) him a gift.
25. If I had a typewriter, I __would type___ (type) it myself. 
26. You could make better progress if you __attended___ (attend) class regularly. 
27. If I knew_____ (know) his telephone number, I’d give it to you. 
28. If you __had arrived___ (arrive) ten minutes earlier, you would have got a seat. 
29. If he worked more slowly, he _wouldn't make____ (not make) so many mistakes.
30. I shouldn’t drink that wine if I __was___ (be) you.
31. If I _find____ (find) a cheap room, I will stay a fortnight.
32. A lot of people _were____ (be) out of work if the factory closed down.