This document discusses the uses of question words like what, which, and how in English. It explains that "what" is used for more general questions without a specific set of options, while "which" implies a small number of choices. "What" is also used without a noun, while "which" usually requires a noun. "How" is used to ask about characteristics like size, quantity, or manner. The document provides examples of questions using these words to clarify their proper usage.