What's he doing?
He's watching TV.
What's this?
a T-shirt
What's he doing?
He's playing the piano.
What's he doing?
He's working/studying. | He's using the computer/internet.
What's he doing?
He's playing the guitar.
What's he doing?
He's playing tennis.
What are these?
socks
What's he doing?
He's playing volleyball.
What's this?
a cap
What's he doing?
He's studying / working / reading a book.
What are these?
boots
What's this?
a jacket
What's he doing?
He's listening to music.
What's he doing?
He's riding a bicycle/bike.
What's he doing?
He's playing basketball.
What's she doing?
She's doing yoga.
What's he doing?
He's swimming.
What's he doing?
He's playing soccer.
What's she doing?
She's reading a book.
What's the man doing?
He's jogging/running.