1 If he doesn't apologize, I'll never invite him again
2.If I were a billionare, I would buy you a plane
4. No matter how old is he, I will marry him
5. If they had followed the map, they wouldn't  have got lost
6. If he phone her immediately, I will get information
7. If it isn't sunny, thw children won't go swimming
9. If Mary wore a cold, she wouldn't get cold
10. If I listened to him, I would get succeed
11.If I hadn't lost my key, I wouldn't have waited in the snow
12.if it didn't rain, the picnic would not be cancelled
13.If Susan ate few icecream, she would not get sick
14.We'll have to back out of the project, if the presentation isn't ready soon
15.If Mary has enough money, she will buy this shirt
16. If the weather isn't find, we won't go hiking this weekend
17. If you don't work hard, you won't pass the exam
18, If she works hard, she will get good marks
19.Unless you are good kid, you are always received gift on Easter day
20. If I had an umbrella, I would not get wet