Is he driving a bus?
Yes, he is.
Is he sailing a boat?
Yes, he is.
Is the cat swimming?
Yes, it is.
Is she riding a bike?
Yes, she is.
What's he doing?
He's riding a motorbike.
What's she doing?
She's listening to music.
What are you doing?
I'm sailing a boat.
Is he riding a bike?
No, he isn't.
Are you flying a helicopter?
Yes, I'm.
What's he doing?
He's reading (a book).
Is he playing football?
Yes, he is.
Is she riding a skateboard?
Yes, she is.
What's he doing?
He's driving a train.