One of the standard questions I try to find out, organically through conversation is what their goals are. And find out what if any obstacles are holding them back from accomplishing those. Sometimes all it takes is to spend some time talking through it, and then following up to see if any action was taken.
Using this approach with one of my clients, I'm helping the ownership develop an internal training program to develop their people in house. It is coming from the business owners need for specific skills and certifications, but also because we want to retain the right people, and giving them a path upward, to responsibility, and higher pay.
If you could ask one burning question about employees, what would it be?
Ha! Didn't mean to put you on the spot @Adam_Fenner. :) Love your approach. I found that so often in my business, I didn't take the time to stop and invest - we were so busy chasing the next customer or payment. I really appreciate your perspective on helping our employees reach their goals as part of reaching yours. Awesome.