Exercise 2
1. is writing
2. is watching
3. is chatting
4. am swimming
5. is sitting
Exercise 3
1. Is Stan riding a horse? Yes, he is.
2. Are Olivia and Martina playing chess? Yes, they are.
3. Are you doing your homework? No, I'm not.
4. Is it raining today? No, it isn't.
5. Are we having fun? Yes, we are.
