According to another contributor's answer to a similar question both "gendre" and "beau-fils mean son-in-law. Since beau-fils can mean either step-son or son-in-law, if you mean to say son-in-law its better to use the word "gendre' to avoid the confusion. I am not a native french speaker, I can only forward what others have contributed.
In a previous lesson, we were instructed to use gendre for both son in law and daughter in law. So why is "Is she your daughter-in-law?" not accepted here? As a side note, all French dictionaries I have checked define gendre simply as "son." Son-in-law is always defined as "beau-fils".
Could you please link to the dictionaries you checked? The 3 dictionaries I checked all listed gendre as "son-in-law" exclusively.
French native speaker on one forum said gendre is used mostly for son-in-law:
- "Beau-fils" can be either step-son or son-in-law, but I think most people's first interpretation of it would be "step-son", as "gendre" is more common for "son-in-law"."
"Est-ce que" is used to indicate a question, and is followed by the sentence's subject and verb (and then the rest of the sentence). One could (roughly, awkwardly) translate as "Is it that"...
Without the "que", "Est-ce" are the subject and verb of the sentence (with inverted order to indicate a question).
"Est-ce que tu as un mouton ?" "tu" is the subject. "Est-ce que" is used to indicate a question. Using the awkward translation, it would be "Is it that you have a sheep?" You could rewrite it as "As-tu un mouton ?", which, interestingly, is the same sentence structure as "Est-ce votre gendre ?"
"Est-ce que vous téléchargez le livre électronique ? "vous" is the subject. "Is it that you are downloading the ebook?"
For this sentence, "Est-ce votre gendre". "ce" is the subject, "est" the subject... so inverting their order is sufficient to indicate a question.
I hope this helps.
NB: I wouldn't recommend actually translating "Est-ce que" as "Is it that" (I'm just trying to give a general idea). To do so might cause a bit of linguistic indigestion for sitesurf et al! (grin)