on one level, i always feel a bit self-conscious (okay, embarrassed) when i draw attention to how professional writers use punctuation; i mean, a close reading of punctuation--what could be more dreary? buti also see punctuation as an intrinsic part of our language, not simply something we "do" to our words. punctuation is not something we invented after the creation of written language; rather, it is something innate to language itself, to discourse patterns, to verbal expression. if that sounds crazy, consider how naturally and even unconsciously we inflect our words when speaking (a stress here, a pause for effect there). inflection in speech, then, is punctuation in print.
here's good example of how professional writers use punctuation to expertly inflect their words. the sentences below are excerpted from a Stephen M. North book review.
"I floundered around a long time seeking just the right way to introduce this review of Louise Wetherbee Phelps’ Composition as a Human Science. The truth is, I really like this book, with emphasis on that present tense; I find myself rereading it, pondering it, defending it, attacking it, recommending it to my students."
North places a comma after the word "is" (something our teachers told us never, ever to do) because he wants to create suspense for whatever his truth-claim will be. perhaps a lesser writer might have chosen the more traditional, blind-obedience-to-the-rules approach, and written:
"The truth is that I really like this book, with emphasis on that present tense;"
in the reworked version, the suspense (the pause) is lost; the reader is halfway through the sentence before he or she realizes its point. North solves this problem by substituting a comma for the word "that." (which is an important point, since it highlights my broader thesis that punctuation and words are not discrete entities, even though we may speak of them as such.)
next, lets very briefly examine why North places a comma after the word "book."
"The truth is, I really like this book, with emphasis on that present tense;"
we've, rightly so, learned not to attach a comma to a dependent clause (bolded below) when it follows an independent clause (e.g., "my dog wags his tail when he's happy," and not "my dog wags his tail, when he's happy.") so why does North break this rule? because he knows that the only rule to follow in writing is the one that helps achieve clarity of expression. or, put another way, if grammar or punctuation rules hinder clarity, ignore them. we don't write to appease robots; we write to express and connect and explain and emote. and we want to do so with as much clarity as we can.
and that's why North places a comma where normally he wouldn't. he wants to make sure the reader understands that the word "with" refers to his "liking." (otherwise, without the comma, readers might unwittingly read "this book with emphasis..." as possessing the same semantic relationship as, say, "The Girl with the Dragon Tattoo" (emphases mine).
moving on. read the sentence again, and ask yourself, why does North break the common-sense rule of placing a coordinating conjunction ("and," "or") just before the final item in a list of three or more items.
"The truth is, I really like this book, with emphasis on that present tense; I find myself rereading it, pondering it, defending it, attacking it, recommending it to my students."
North is signalling that his list is non-exhaustive. in other words, when you omit the final "and," you are telling the reader that your list includes only the most salient items. (example: "my grandmother was always baking something sweet--muffins, pastries, cakes." omitting the final "and" lets the reader know that the grandmother baked many more sweets than the three listed.)*
one final point.
North puts Composition as a Human Science in italics. as a writing teacher, i am frequently asked whether book titles get underlined, italicized, or put in quotes? the short answer: book titles should be italicized. that's the conventional standard. end of story. the long answer is that, well, it depends. when writing by hand, for example, we underline book titles, since we can't--at least not systematically--italicize our handwriting. also, a few publications (The New Yorker magazine, comes to mind) put book titles in quotes. it doesn't really matter which method you adopt--italics, underline, or quotation marks. what matters is that you understand why we inflect book titles (or any titles, for that matter) in the first place: clarity.