Bonjour Antonios, Both "il faut faire son lit" and "Il faut faire ton lit" are correct, but there is a slight difference. If I say "ton," that means I'm talking to you, Antonios, specifically. "Il faut faire son lit" is speaking generally - everyone must make his or her bed. In English, we can also use "you" here, meaning not specifically you, Antonios, but you/everyone in general. Yes, you can also say "Il faut faire mon lit, il faut faire notre lit," etc.