Answer:
1. If there are delays on the train, we will miss our flight.
2. When I use environmentally friendly products, I feel that i'm making a difference.
3. John usually goes to work by bike unless he wakes up late.
4. If you don't want to go to the concert, I'll give your ticket to someone.
5. Unless it rains, we will be at the match tomorrow.
6. If we don't change our behavior, our planet will die.
7. I won't say anything to Phil if you tell me not to.
Explanation:
Zero and first conditionals may look similar at first. Let's highlight their difference below:
- Zero conditional uses the present tense or the present continuous. Its purpose is to talk about what generally happens, what is usually true. For instance, saving electricity is good for the environment. Therefore, we could say: "If you save electricity, you are helping our planet."
- First conditional uses the present tense for the condition, but the future tense for the consequence. Its purpose is to talk about a specific situation. For example, your father may have told you he will give you a present if you save electricity. Therefore: "If you save electricity, your father will buy you a guitar."