I generally don't ask them the questions straight up other than their name as I introduce myself. I'll ask 'em questions or talk about things that pertain to person, place, time, and event (or purpose e.g. "What brought you to this Safeway (grocery store) today?", which you'd expect the answer to be similar to "buy groceries"), but it's not as straight forward as asking "What's your name? Where are you? What day of the week (or what month is it)? What happened?" like I would ask in class, and I'll ask multiple question (not just one per criteria) to confirm whether they are oriented. I'll look for their reaction and carefully listen to their response. I like to believe that if they aren't oriented, it's easy to tell just by taking with them. You can pickup on their facial reaction, what they are doing, how they answering things, and the disconnect between me and them.