In a remote village, happened to live 4 tooglers and a truth teller. If in appearance nothing could distinguish a toogler from a truth teller, in effect, things would be different: a toogler has the annoying propencity to alternate between answering truly and answering wrongly. As an example, ask a simple question such as "Are you a toogler?" to a toogler, he would then first start by saying YES if he is currently saying the truth, but if asked twice, the toogler would answer NO, since he would currently lie, and then keep alternating YES, NO, YES, NO, ad infinitum. Oppositely, the truth teller is a constant person, and always answer truly to a question. In that sense, would you answer repeatedly "Are you a toogler?" to a truth teller, she would answer YES, YES, YES, ad infintum.
One day, a traveller happened to go through the village, and met the five inhabitants. They asked him the following question: "can you, with two questions, discover who is the truth teller?"