1. If you give me your address, I will write you a letter.
2. If you don't get tickets for the Philharmonic, we will stay at home.
3. If you don't eat, you get hungry.
4. If it rains, we will have to stay at home.
5. If you drop ice in water, it floats.
6. If you don't call, I will be upset.
7. I will cook dinner if I am not tired.
8. When we sleep, we usually dream.
9. If my friend is at home, he will tell us what to do.
10. If you don't buy coffee, we will drink tea.
11. If he is free tomorrow, he will certainly come to our party.
12. If you ring me up, I will tell you a secret.
13. If he doesn't pass his exams, he will not get a scholarship.
14. If you don't study, you may fail the test.
15. I will buy you a present if I have enough money.
16. When you run fast, you get tired.
17. If you go to the party, I’m sure you will have a good time.
18. If we buy a car, we won't have to travel by train.