'Il faut ranger sa chambre' means 'You have to tidy your room' but referring to people in general, not referring to someone in particular (i.e. like if you're telling your son to clean his room), in which case you would say 'Il faut ranger ta chambre' or I think even 'Il te faut ranger la chambre' would work, as well as Il faut que + subjunctive 'Il faut que tu ranges ta chambre'.

If you want to say 'You must tidy his/her room' as in telling someone to clean another person's room then I think you need to use the Il faut que + subjunctive construction - Il faut que tu ranges sa chambre

Nick

It's an interesting question which has got me thinking.

In the general sense, I have to say I would normally just say 'Il faut ranger la chambre' rather than 'Il faut ranger sa chambre'. Is the former incorrect then? Or are their subtle differences between 'Il faut ranger la chambre' and 'Il faut ranger sa chambre'?

Nick ‘il faut ranger la chambre’  - la chambre is specific, so only works when discussing a specific known room - ‘ the (bed)room ‘. 

Hi, 

According to the lesson: Il + pronom + faut+ nom. Pourquoi y-a-t-il "de" dans: " Il lui faut de l'aide"? Je ne comprends pas. SVP, expliquez-moi! Merci d'avance

Hi, 

According to the lesson: Il + pronom + faut+ nom. Pourquoi y-a-t-il "de" dans: " Il lui faut de l'aide"? Je ne comprends pas. SVP, expliquez-moi! Merci d'avance

Hi, 

According to the lesson: Il + pronom + faut+ nom. Pourquoi y-a-t-il "de" dans: " Il lui faut de l'aide"? Je ne comprends pas. SVP, expliquez-moi! Merci d'avance