The rules
- For things that are always true, use the present tense in both parts (zero conditional): If you heat ice, it melts.
- For a real future possibility, use the present after if and will in the result (first conditional): If it rains tomorrow, we will stay inside.
- For an imaginary present, use the past after if and would in the result, with were for be (second conditional): If I were taller, I would play basketball.
- For an imaginary past, use had plus the past participle after if and would have in the result (third conditional): If we had left earlier, we would have caught the bus.
- A mixed conditional joins a past condition to a present result: If she had studied medicine, she would be a doctor now.
- After wish and if only, use the past for the present and the past perfect for the past: I wish I knew the answer.
- Unless means if not, so it takes a positive verb: Unless you hurry, you will miss the bus.
This time: 0 right, 0 wrong