Articles in a metaphorical sentence Hi! In my English class, we bumped into a problem regarding a certain sentence in an exam. “Jack Kilby will always be remembered as the inventor of A device that is THE engine of the information age.” The articles written in caps are what we discussed. I would agree that the A could be considered wrong, but I don't see why I can't use THE in the second case, it seems quite natural to me. Also, there was another sentence I'm not so sure about. “Jack Kilby is an engineer. He is A man who in 1958 invented…“ Aren't both allowed here? (I do see the slight change in the feel/meaning of the sentence that would happen.) Thank you very much for your help.