Q. Realizing that every style guide I have read states that periods always go inside quotation marks, I argue that, if a quote is only a part of a sentence, the period at the end applies to the entire sentence, and not just to the quoted part; therefore, it should be placed outside the closing quotation mark. Does this reasoning “hold any water” at all?
A. Sure—but for style rules, unlike buckets, holding water isn’t always the main goal. Although the British agree with you and punctuate accordingly, the time-honored convention in American-style punctuation is to put the period inside the quotation marks.