1. When the traffic lights are red, we do not cross the road.
2. When you leave the ice in the sun, it melts.
3. When my mum is busy, I help her with the housework.
4. When you heat the water to 100 degrees Celsius, it boils.
5. When you eat a lot of sweets, you get fat.
1. If I see Tim tonight, I will give him your message.
2. If she is not busy, she will come with us.
3. If you do not work harder, you will not do better at school.
4. If we tell Dad about the broken window, he will not be angry.
5. If he takes an aspirin, he will feel better.