Is that a hat? I teach English at various schools and colleges in Japan. In one of these places, there is a text-book for beginners that offers the following example: Ken: Is that a hat? Mary: No, it isn't. It is a scarf. My question is: How useful is this example? Does any normal human being often use this question? Or is it the kind of question that is only used in very rare circumstances- maybe if you are The Earl of Carnarvon exploring Tutenkhamen's tomb, or pos...