1. If I study hard, I'll pass the exam.2. If you heat water, it boils.3. If I were you, I would reconsider my decision.4. If we pour oil in water, it floats.5. He would like it if he tries.6. If I have time, I will visit Granny.7. If I had known, I would have come.8. If he knew her number, he could send her a message.9. If we try harder, we might succeed.10. She could have gone abroad if she had a month off last year.11. What will happen if it rains? If I had a daughter, I would give her my mother's name.12. They will pay if they can.13. If I had told you the truth, you might have understood.14. I will make a mistake unless you give me directions.15. If the cake weren't burnt, I could eat it.16. If Wendy hadn't arrived late, she wouldn't have missed her appointment.17. Would you help me if I needed it?18. I wouldn't have watched the film if I had known it was so boring.19. Birds fly south if the weather gets cold.20. Unless I were you, I would punish them.