When a U.S. citizen and an immigrant get married, they may apply for a green card using their marriage as the basis to request permanent resident status. This does not mean that the immigrant was necessarily out of status to begin with. They may have been in the country on a short-term visa, such as a student visa. But they are seeking permanent resident status so that they can stay indefinitely with their new spouse.
As part of this process, the government may ask that person to come in for a green card marriage interview. The basic goal of this interview is simply to determine the authenticity of the relationship. This is to prevent fraudulent cases in which people pretend to be romantically involved just so that one of them can secure a green card.
How can you prepare?
This means that you cannot prepare for a green card interview in the traditional sense. There is nothing to study, and there is not a set list of questions that you know you are going to be asked. This is much different from something like a naturalization test, where you can study to ensure that you understand how the U.S. government works, for example.
One way to prepare is by gathering any documentation that helps prove that your marriage is authentic. This could include evidence that you live together, such as copies of your lease or utility bills in both of your names.
But when you are asked questions during the interview, they will generally relate to your relationship. Examples include questions about when you met, what roles or responsibilities you have around the house, what the two of you like to do together, when you got married and much more. The answers are going to be unique in every case, but the government simply wants to see that you and your spouse provide similar answers and show that your marriage is real.
Whether you are getting a green card or worried about your status, it can be helpful to work with an experienced immigration attorney.