Q. CMOS says that you’re supposed to capitalize after the colon when the colon introduces (1) a quotation or (2) multiple sentences. But when sentences follow the colon how do you know if they’re sequential enough to warrant the capital? It’s usually really hard to tell.
A. Take heart: As of the 18th edition, CMOS now advises capitalizing any complete sentence that follows a colon. See chapter 6, under “Colons.”