What's he doing?
He is riding his bike.
What's he doing?
He is playing with a boat.
What's she doing?
She is skipping.
What's he doing?
He is running.
What's she doing?
She is riding a bike.
What's he doing?
He is playing with a ball.
What's she doing?
She is jumping.
What's he doing?
He is riding his scooter.
What's she doing?
She is playing with a ball. / She is playing football.
What is she doing?
She is swimming.