The question that you can never answer yes to is "Are you asleep yet?". Another question that you can never answer yes to is "Are you dead?". These are examples of questions that cannot be answered with a "yes" because if you are asleep or dead, you cannot respond with a "yes" answer. There are also other questions that cannot be answered with a "yes" depending on the context and intonation of the question, such as "Is everything you say a lie?".