В первом предложении пропущено местоимение, потому на выбор:

1. What are you/we/they doing next Friday?  / What is he/she doing next Friday?

2. He is going to work for his father when he leaves school.

3. They are having a party tonight.

4. He is playing in a football match this afternoon. Let's watch him.

5. I'm tired. I am going to sleep this afternoon.

6. We are flying to America tomorrow morning. Look! Here are the tickets.