Подчеркните правильное слово:

1.This is easy.You can't/can do it!
2.I can/can't speak Spanish.I only speak English.
3.Mark can/can't play tennis.He plays on Tuesdays.
4.Sara can/can't play the piano.She's a good musician.
5.The baby can/can't walk yet.
                                                      Помогите плиз:)