If you heat water to 100 degrees, it boils.
If it rains tomorrow, we'll go to the cinema.
If I had a lot of money, I would travel around the world.
If I had gone to bed early, I would have caught the train.
If I drink too much coffee, I can't sleep at night.
If you don't hurry you will miss the train.
If you had studied harder you would have passed the exam.
If it had rained you would have gotten wet.
If we had looked at the map we wouldn't be lost.
If this thing happens that thing happens.
