Here is a chart to help you to visualize the basic English conditionals. Do not take the 50% and 10% figures too literally. They are just to help you.
probability | conditional | example | time | |||
100% | zero conditional | If you heat ice, it melts. | any time | |||
50% | first conditional | If it rains, I will stay at home. | future | |||
10% | second conditional | If I won the lottery, I would buy a car. | future | |||
0% | third conditional | If I had won the lottery, I would have bought a car. | past |