When we ask questions, what are we doing? Is it only a request for information? Can it be something else? What is the point of a rhetorical question? Are there such things as rhetorical questions in all languages? Do they mean the same thing in all languages?
I think questions often communicate more information than they seem, mostly about the person speaking and about the context it's spoken in. Most people would assume that an art history professor asking "Who was Picasso?" is asking a different question from a 6-year-old boy asking "Who was Picasso?" In both cases the words are identical, but the meaning is (probably) very different.
So what do words mean?