is he doing his homework?
yes, he is
Is she listening to music?
yes, she is
Is he watching TV?
Yes, he is
Are they drinking?
No, they aren't
Are they playing the guitar?
No, they aren't.
are they watching TV?
No, they aren't. They're playing the guitar
Are they playing?
No, they aren't
Are they listening to music?
yes, they are
Is she playing the guitar?
No, she isn't. SHe's playing the piano
Is he eating?
Yes, he is