Subscribe to The Chicago Manual of Style Online
Q. Is it correct to have the exclamation point or question mark immediately after the period in each of the following sentences? He said he’d be there at 5:30 a.m.! Is your name John Smith Jr.? I know that since at least 1993 CMOS has encouraged writers to avoid unnecessary commas (Is your name John Smith, Jr.? She works for Time, Inc.). However, there has not been a similar assault on periods. I am not complaining, but I wonder about the above sentences involving a period and punctuation immediately afterward.
A. It’s useful to distinguish punctuation that’s part of a word from punctuation that ends a sentence. A period that is part of a word (such as an abbreviation) cannot be replaced by any other punctuation besides a sentence-ending period. So yes, retain the question mark and exclamation mark, as you would a colon, semicolon, or comma.