$IV.$
1/ If I were the Prime Minister, I would help the homeless people.
2/ He could buy a new car if he had enough money.
3/ If I had more time, I could read books.
4/ If he hadn't been ill, he could have gone to school.
5/ They could have passed the exam if they had studied hard.
6/ We could have come with you if we weren't busy.
7/ If her parents had been richer, she would have studied abroad.
8/ If he had come yesterday, she would have given him a present.
9/ If he hadn't rained, we would have gone for a picnic.
10/ The world would be a better place if the environment weren't polluted.
$V.$
1/ If you don't keep silent, you will wake the baby up.
2/ If you don't leave immediately, I will call a policeman.
3/ If I knew her phone number, I would ring her up.
4/ If you don't go right now, you will late for the train.
5/ If she weren't absent from class, she could keep pace with her classmates.
6/ If I had known Alice's address, I could have written to her.
7/ If I knew the answer, I could tell you.
8/ If we had had a map, we wouldn't have got lost.
9/ If his friends hadn't been so late, they wouldn't have missed the train.
10/ If today were Sunday, the pupils could go swimming.
11/ If it hadn't been rained heavily, everybody could have gone out.
12/ If this chair weren't heavy, he could move it.
13/ If he hadn't gone out in the rain last night, he wouldn't have had a flu.
14/ If the church bells didn't rung, I could sleep.
15/ If I do exercise, I will feel better.
16/ If you don't stop talking, you won't understand the lesson.
17/ If the boy weren't young, he could go to school.
18/ If there weren't a fridge, the food would spoil.
19/ If you don't study hard, you won't passed the exam.
20/ If you don't stop smoking, you health will become worse and worse.
21/ If you arent't careful, you will cut yourself with that knife.
22/ If you aren't calm, you will make a wrong decision.
23/ If there weren't air, we would die.
24/ If she hadn't had a visa, she couldn't have come to that country.
25/ If there weren't the sun, man would live in the darkness.
26/ If he hadn't had money, he wouldn't have bought such a big house.
27/ If he didn't smoke, he wouldn't be so weak.
28/ If it hadn't been very cold yesterday, we could have gone swimming.
29/ If it weren't cold, we could go swimming.
30/ If I hadn't been busy, I would have watched TV last night.
