E-2 Investor Visa - what questions might be asked in the interview?

Hello everybody,

This might be odd but I'm not an applicant, I'm on the other hand interpreter and will be taking part in an interview during which a lot of questions will be asked to the applicant.

This is my first time (with an American embassy) and I'm a little bit nervous. Do you know what questions might be asked or is there anything special I need to know so I can prepare myself properly?

Thanks in advance!