I am a US citizen and sponsoring my father. What are the questions asked at the initial interview with immigration office?

I assume you are referring to the adjustment of status interview with your U.S. Citizenship and Immigration Service's local office. Your father should be familiar with the content of his application, and be prepared to respond to both the questions listed on the I-485 Application to Adjust Status, as well as other questions the officer may ask. Generally, the officer wants to verify that the applicant is in fact related to the U.S. citizen petitioner, and that the applicant has nothing in his immigration history that would prevent him from obtaining a green card.

Lisa's right. The officer might also want to be sure that your relationship with your father has been legitimated, so having a copy at the interview of your parents' marriage certificate showing they were married before you were born might also be helpful.

Good luck!

Daniel Shanfield
www.immigration-defense.com

This answer is not to be considered legal advice or to create or constitute a lawyer/client relationship. It is not intended as a substitute for legal counsel, and no one should act upon any information contained herein without seeking legal counsel.

Another suggestion is for you (the sponsor) to bring an updated I-864 affidavit of support with updated financial/income verification documents such as your last 3 paystubs and latest tax returns, to the adjustment (I-485) interview. So double-check to make sure that you have income to meet 125% of the poverty guidelines. In my experience, the sponsor can sign the updated Form I-864 in front of the USCIS officer at the time of the interview.

[Note: This is for general information purpose only, not intended to be legal advice and does not create an attorney-client relationship].

I'm not sure where you reside, but in many jurisdictions, you will not need to go for an interview when you sponsor a parent. In the event that you are questioned, they will probably ask you about your immigration status, your relationship with your father, and possibly your financial situation. Each officer has broad discretion on what to ask at the interview.