You have to ask the really hard questions. Like the ones every 5 yo could answer without thinking. E.g. try: "What can you do with a car/book/gun?" Be suprised

You have to ask the really hard questions. Like the ones every 5 yo could answer without thinking. E.g. try: "What can you do with a car/book/gun?" Be suprised the answer isn't drive/read/shoot^^.