Quick, name the punctuation error that irritates you the most. "It’s" used for "its"? A comma used in place of a semicolon? An apostrophe used to make a noun plural (shudder)?
Think of the most appalling, egregious, everybody-knows-this-is-wrong mistake, and I will show you a punctuation usage that was correct at one point in time or will be correct at some time in the future.
Punctuation, like language itself, is a constantly evolving art; that means that nothing stays wrong, or right, forever. For six thousand years of written language, no one made spaces between words. You can imagine the headache – but it didn’t matter. The text was being used for a different purpose, and the idea of actually inserting spaces, let alone marks indicating how to make sense of a sentence, was disdained as a tool that would make reading something that everybody could do.
That's why the great Roman orator Cicero had nothing but scorn for those readers who relied on punctuation, for the end of a sentence “ought to be determined not by the speaker’s pausing for breath, or by a stroke interposed by a copyist, but by the constraint of the rhythm,” he declared. Guilty as charged, I guess, although as a voice from the future I'll point out that there are some advantages in being able to understand a text in one quick read-through, instead of spending days deliberating over how to separate the words or where to end a phrase.
However, this view does open up the possibility that those of us who adhere strictly to certain rules of marks and spaces are distinguished less by our great learning than by our narrowness. Why shouldn’t we put an apostrophe “s” after a word that wants to be plural, after all? The important thing is the power of delivery and the incisiveness of the reasoning. Punctuation is just marks on a page.
This is why when nervous first-time authors ask where the right place is to put a certain comma, or when lordly dons of the senior author cohort like to tell me I have it wrong because I’m not doing it the way they were taught back in 1950 – I first state the rule that applies, and then add, “according to the current AP Style Guide. Other authorities will tell you differently.”
That’s because punctuation, like spelling, or like deciding on which side of the road to drive your car, is convention, and conventions are only as binding as people make them. Someday, it will be fine that educated people prefer to take they're dog's for a walk. In the meantime, though, understand that while punctuation may be contextual, your use of it is telling the listener volumes about your own personal context. Such as: he probably learned to read in a barn.
Emily Wortman-Wunder is managing editor for the SME publications Minerals & Metallurgical Processing and Transactions, and she has never (yet) rapped anyone on the knuckles for using 's to make a noun plural. But it's probably just a matter of time.