Almost every job interview ends with an opportunity for you, the candidate, to ask questions. Don't treat this time as another chance to impress. Instead, use this time to assess your future boss. Ask your potential manager about a past project. This should give you a sense of how she works. Inquire about customers or colleagues. Her attitude toward others may reveal how she treats people. Watch how she answers the questions. Does she talk about herself a lot? Does he take credit for accomplishments? This data can help you better understand the manager you are getting along with the job offer.
Source: "Choose Your Boss Wisely" by Priscilla Claman