The interview process went really smooth for us since I speak fluent english and we had a large binder filled with evidence of our engagement and proof of our relationship. My wife has been to Algeria three times and we saved all of the documents and pictures to use in our evidence which we referenced at the interview. You can expect to be asked any kind of questions and very personal questions such as what's her favorite color, what she does for a living and about her family members and their jobs. The most important thing is that if you speak very good English. And of course wear your engagement rings why would you not. Plus you will want pictures from your engagement party to show as evidence as well and pictures with different family members in them not just you two.