Vous pouvez m'aider ex32. Merci

Exercice 32 : 

1. I can't play the violin. I must learn. 
2. He can ski very well, but he must be careful.
3. I can't go to the cinema with you. I must help Mum. 
4. It's a very good film. You really must come with me.
5. How well can he dance ? He can't dance at all.