Is he playing computer games?
No, he isn't.
Is he doing his homework?
Yes, he is.
Are they watering the plants?
Yes, they are.
Is she playing the piano?
No, she isn't.
Is he eating breakfast?
No, he isn't.
Are they making a cake?
No, they aren't.
Is he writing a book?
No, he isn't.
Is she cleaning?
No, she isn't.
Is she doing the washing up?
Yes, she is.
Is she riding a bike?
Yes, she is.
Are they making the bed?
Yes, they are.
Is he listening to music?
Yes, he is.