Hyphens, En Dashes, Em Dashes
Q. Can an em dash be used to connect two complete sentences? For example: “You don’t need to go to the DMV in person to renew your driver’s license—you can renew it online.” Thank you in advance for your answer!
A. The em dash is the chameleon of punctuation marks. It probably wouldn’t get away with trying to impersonate a question mark or an exclamation point, but it can stand in for just about any of the other standard sentence marks. Your example is (almost) a perfect illustration. It could be written with a semicolon, a colon, or a period (or a pair of parentheses) in place of the dash—but the dash adds a bit of emphasis that’s in keeping with the relatively informal tone. (A dash can also take the place of a comma, but a comma in your example would be considered a comma splice.)