Does anybody know what kind of questions are asked at an immigration marriage interview?

They ask general questions in three different areas (1) immigration status, (2) marriage and (3) grounds of inadmissibility (ineligibility for permanent residence).

Most people are concerned with marriage questions. While every officer is different, they usually ask open-ended background questions such as: how did you meet; how long have you known each other; questions about relatives; work; details of the engagement or wedding, etc. please note that the officer is generally not looking for a certain answer; they are looking for (1) inconsistencies with information provided on the forms and (2) you and your spouses response/reaction to questions.

If you are married, living together and pay some attention to your spouse, both of you should do fine. The officers generally understand you may not be able to answer exactly some of the questions, but they ask questions that spouses generally know about each other if you have a shared life together.

The officer will generally not ask any embarrassing personal questions, but if there is no cohabitation, they can certainly ask if the marriage has been consummated. Do not take offense to that question.

It may be worthwhile to meet with an immigration attorney for an interview preparation as he/she should have good insight regarding the practices of the local field office.

Thanks a lot for your advice , very helpful, hopefully we find a good attorney.