Citation, Documentation of Sources
Q. Please, please settle this question about questions for me! A colleague insists that the following construction does not require a question mark: “I had to consult an authority. What would The Chicago Manual of Style say.” Another example: “I got a new bike. How cool is that.” CMOS indicates that a question mark is not required for indirect or courtesy questions, but a question, even if it is not being asked of someone in dialogue, is still a question. Who’s right?
A. When a sentence structured as a question doesn’t end with a question mark, it conveys the tone of voice we use when we don’t really expect an answer. The first example you give, however, seems to be an actual question. If it isn’t—if your colleague means it to sound like “I drank everyone under the table; what would Grandma say”—then fine. But actual questions require question marks.