1. She's looking / looking at boots in the shoe shop.
2. They not buying / aren't buying those T-shirts.
3. Are you coming / You are coming with us?
4. Yes, I'm / I am
No, we aren't / isn't.
5. To talk about facts, habits and routines, use the present simple / continuous.
6. To talk about an action in progress, use the present simple / continuous.