They your friends? -yes,they he your brother? -yes,he he ride a bike? -no,he you want to play with the boll? -no,i she roller-skate well? -no,she your friend want to play the piano? -yes,he is,are,do(2),does,don't,doesn't(2),can't.

1) Are they your friends? Yes, they are.
2) Is he your brother? Yes, he is.
3) Can he ride a bike? No, he can't
4) Do you want to play with the ball? No, I don't.
5) Can she roller-skate well? No, she can't.
6) Does your friend want to play the piano? Yes, he does.