The “Oxford comma” is the one placed before an “and” in a list of three or more. It’s the subject of an embittered battle among grammar-lovers. You can make up your own mind. Sometimes it’s correct to use it; sometimes it’s more fun not to.Lisa Wade, PhD is a professor at Occidental College. She is the author of American Hookup, a book about college sexual culture, and a textbook about gender. You can follow her on Twitter, Facebook, and Instagram.