"What is your name and where is your house, sir?"
Translation:ما اسْمَك وَأَيْن بَيْتَك يا أُسْتاذ؟
Asking where somebody's house is is strange, like you think they own the house but don't necessarily live in it. In Arabic, to ask "where do you live?" you say "أين تسكن؟" (ayna taskun[u]) to address a man, and "أين تسكنين" (ayna taskuniin[a]) to address a woman. That's if you're referring to an address. If you want to ask what city or country they're living in, you'll be more likely to phrase it أين تعيش\تعيشين (ayna ta3iish[u]/ta3iishiin[a]).
That's like asking whether "mister" or "sir" is better. They're both just... there; I wouldn't say there is a clear winner in terms of actual usage, at least as far as Standard Arabic is concerned. Now if we were talking about dialect, then أستاذ is much more common, at least in the dialects I know.
(1) In Standard Grammar (taught in all schools), it is 2ismUka/i (with Damma on "2ism") for the nominative case. (2ismUka is "your name" to a male, 2ismUki is to a female).
(2) In some local dialect, it is 2ismAk for any cases -- which means "your name" to a male. (2ismik is to female).
In the previous sentence, I had to choose between ismak without kasra under the alif and ismak with kasra. I chose kasra and was told it was wrong. I don't know if this is a duolingo error or if there is an actual distinction. This time I chose kasra again, and it was accepted. I THINK it was an error... Anybody have an opinion?