thatisapen改成否定句為
That isn't,在that is的is後面加not就是否定形式。that is在英語中很常見,例如:that is an apple.那是一個蘋果。
that isn't a tomato.那不是西紅柿。
that is a pencil.那是一個根鉛筆。
that isn't a pen.那不是鋼筆。
that is cat.那是一隻貓。
that isn't a dog.那不是狗。