French language Q&A Forum

What does mettrai mean

Can we not just use ''Elle est ma soeur'' and ''Il est le fils de Martha'' ?

Edit: Nevermind, I asked my French friend who told me that you specifically cannot say 'Il/elle est un/une/mon/ma etc' 

This rule only applies to the pronouns 'Il' (he) and 'Elle' (she). 

So I've answered my previous question, so No you cannot say ''Elle est ma soeur'' it has to be ''C'est ma soeur''

I felt like it wasn't explained very in the lesson! (sorry!)  I hope anyone seeing this message finds this helpful.

In order to say, "i prefer our houses to theirs" is it acceptable to say, "Je préfère nos maisons à les leurs ." ?

As an aside, I found it so easy to add accents in this new format. It is a super improvement indeed! 

Une maison  à vendre.  

des travaux à faire,

Could the postman say “je fais un boulot important”?

I still don't understand whey, "Qu'est-ce que le fois gras," Is not an acceptable way of saying "What is?" QUE (what) est-ce (is it) le fois gras.

Why is it any less acceptable than "Qu'est-ce que c'est que" The explanations just don't make sense to me. Could you clarify?