3.
1) If I see John, I will tell him your news. 2) He will be very pleased if it is really true. 3) If you go to town on Monday, you will meet my brother Tom. 4) If you need help, my father will help you. 5) We will have a picnic lunch if the day is fine. 6) If you ask a policeman, he will tell you they way. 7) I will finish the job tomorrow if I can. 8) I won`t require an umbrella if it doesn`t rain 9) If she thinks it over carefully, she will form a clear opinion. 10) If they catch the bus now, they will arrive at half past nine. 11) He will find the answers if he looks at the back of the book. 12) If you want me to, I will come for a walk with you. 13) If he writes to her, she will answer at once. 14) If you wait a few moments, the waiter will bring your coffee. 15) He will lose weight if he stops eating too much. 16) If she is patient, I will try to explain. 17) I will wear a purple tie only if I must. 18) If we leave at once, we will catch the early train. 19) If he does that again, his father will punish him. 20) If she drinks this medicine, she will feel much better .
4. 1) If l knew, I would tell you. 2) If she wanted to talk, she would ring up. 3) Her health would improve, if she slept longer. 4) if he had enough money, he would buy a large house. 5) She would feel lonely if Peter went out every evening. 6) We would be pleased to see you if you arrived. 7) If we could come on Sunday, we would come. 8) I would understand Mr. Smith if he spoke slowly. 9) We wouldn`t go by ship unless there was on other way. 10) If you gave him good meals, he wouldn`t be able to work hard.
5. 1) If she had been tired, she would have been better. 2) He would have done more work if he had been able. 3) I should have lived better if I had earned more money. 4) If I had known the answer, I should have told you. 5) He wouldn`t have come unless you had invited him. 6) We shouldn`t have remembered it if it hadn`t been so strange. 7) If I had had time, I would have helped you. 8) Peter would have come if you had wanted him to. 9) If you had written more often, you would have received more letters. 10) They would have preferred it to be kept if they could. 11) I would have bought it by myself if I had had money. 12) If they had offered it to me for nothing, I wouldn`t have taken it. 13) I should have broken a promise, if I had answered your question. 14) If you had sworn to keep a secret, I would have told you
Примечание: В 5 упражнение 11 предложении я не уверен.
№3
1. see will tell
2.will be is
3. go will meet
4. need will help
5.will have is
6.ask will tell
7.will finish can
8.will not require doesn't rain
9.thinks will form
10. catch will arrive
11.wiil not find look
12. want will come
13. writes will answer
14.wait will bring
15.will lose stops
16. is will try
17.will wear must
18.leave will catch
19.does will punish
20.drinks will feel
№4
1.knew wouldl tell
2.wants will ring up
3.will improve sleeps
4.had would buy
5.will feel goes
6.will be arrive
7.can will come
8.would understand spoke
9.will not go is
10.didn't give wouldn't ba able to
Объяснение: