I don't know what grammar is. Not really.
I've never been entirely sure exactly where the line is drawn between grammar and other writing issues, such as usage and syntax. And I don't think I really need to.
As with anything, plenty of issues clearly fall into one camp or another. For instance, verb conjugation is a matter of grammar; spelling errors are not. But other situations are not as clear cut, and sometimes trying to see where grammar ends and usage begins is like trying to see where blue ends and purple begins.
I could give you some examples of where I think things get muddled, but some reader would take the time to tell me where my examples should fall in the linguistic spectrum. And then someone else would disagree with the first person's evaluation, and thus would begin a protracted and pointless back-and-forth.
And that's not the point I want to make. My point is this: I don't really need to know what grammar is.
This might sound odd coming from an editor, but give it a little thought. I'm not saying that I don't need to know the rules and guidelines of grammar. I'm saying that I don't need to know what qualifies as a grammar issue, or usage issue, or a punctuational or morphological or syntactical or psycholinguistic issue. An editor never works in just one of these worlds. An editor, instead, focuses on good writing, which takes in grammar, usage, style, tone, and so much more.
Yes, a good editor needs to know what are rules (it's vs. its), what are guidelines (parallel structure), and what are matters of style (Oxford comma vs Nazi comma), but more important than any of these is the quality of the piece of writing. Grammatical writing isn't always good, and good writing isn't always grammatical.
A good grounding in grammar is important, for anyone. But by that I mean an understanding of the basic mechanics of how our language works and how sentences are put together. But no, editors and writers don't need to know which linguistic cubbyhole to confine each little thing to, any more than your average person needs to understand kerning, ligatures, and serifs in order to read.
And I'm alone in this belief. National Grammar Day isn't very old, but already it has generally expanded to cover all types of editorial issues, and not just grammar. for instance, the winner of this year's National Grammar Day tweeted haiku contest* was of a more general editorial vein, and the second through fifth place entries and the honorable mentions included haiku about (mis)spelling, punctuation, and language peeves.
Yes, grammar is a thing, and for smooth and interesting communication, it's an important thing. But don't get so caught up in the minutiae of grammaticality that you lose what was good about a piece.
Grammar is only a small part of writing. Any good editor knows this. Any good writer knows this. Any avid reader knows this.
If you agree at all, help me prove it. I would love to hear your examples of "bad" grammar used in great literature, shared in the comments below.
* For what it's worth, I tweeted two entries to the National Grammar Day tweeted haiku contest:
Not a whole colon,
But a vampire emoji:
Two semicolons.
The subjunctive mood
Would not have been created
If I had been king.
[UPDATE, later that same day: There is a certain (rather large) aspect of all this that comes only after years of experience. I had that in mind when I began this post with the fact that I have been editing for over a decade, but in my haste to get this online, I forgot to pick up that thread.
Grammar is important, yes. But after years of writing and editing, everything I have learned has cohered into one mass of word-ness, and I draw from that mass when I write and when I edit.
I used to know a some grammar. I used to be able to show you the difference between past progressive tense and past perfect tense. I can't do that anymore with out looking it up, but -- and here's the important part -- I can use those tenses correctly.
The same is true in math. Once the Pythagorean Theorem becomes a part of your mathematical toolbox, you don't care whether the theorem is technically algebraic, geometric, or trigonometric. You just use it.
Like math, writing and editing are skills learned in pieces, but the pieces make up an entire spectrum of a larger whole.
Over time, the science of grammar yields to the art of writing and editing. It's really a much simpler idea than perhaps I made it out to be. ABH]
[UPDATE #2, on 3/6/13: Jeremy Butterfield wrote a nice post about what grammar is and is not, and how blurred that distinction can be, over at his blog.]