Who are copy editors and what do they do anyway? The short answer is that they are the secret heroes of publishing. They use a keen eye to spot grammatical errors and typos. In addition, a copy editor knows how to find and fix factual errors. The best copy editors also call attention to faulty logic, or holes in an article, or paragraphs in the wrong place. And the very best are sentence magicians, turning clunky collections of words into musical phrases.