Right, let's start with this blog's theme song. All together now:
They're tools, not rules!
Okay. And having let off a bit of steam and told the world where we stand on this issue, I'd like to remind you about the rule that a sentence should have a full stop at the end. And the one that says you should have started that sentence with a capital letter. And please remember to keep the rule that you should start writing at the top, left-hand corner of the page and write horizontally. Shall we agree that those are as close as you can get in writing to laws that should not be broken, because they're basic to us reading anything fluently?
Then there are what you might call the second-order rules, which are about being understood. High on the list of those are things like dangling participles, the agreement of pronouns and separating lists with commas, which work to transmit the writer's meaning, via the black marks on the page, to the reader's understanding. If you break the rules of how our grammar, syntax and punctuation work then at best our fictional dream will be blurred or broken, and at worst we'll get the giggles at what you've actually said. These are the nearly-rules of how language is used. You may hold to the formal, or informal, conventions, but they should be kept because meaning is always paramount.
In non-fiction, that's all you need to worry about. But in fiction and creative non-fiction we're always working partly with human voice, and in speech humans bend and break the rules of written language all the time. So the second-order rules of grammar and syntax need refining: particular dialects and groups and even individuals express themselves according to different sets of conventions, and you may want to let those colour your writing. That's obvious in dialogue but, crucially, you need to be working with it in how those voices are evoked in narration and reported speech too - He said it'd be a right carry-on and he weren't having none of it - and its close cousin, free indirect style.
That voice needn't be conversational, of course, nor that of a character. It can be a voice in the larger, more metaphorical way we use the term: the words in which a particular consciousness and sensibility expresses itself. That includes working with echoes and repetitions, with images and metaphors, and with sound: rhythm, pattern, rhyme and half-rhyme, assonance, alliteration. So of course you might bend the conventions of formally or informally correct grammar to get the effect you're after. But your reader must still understand you - meaning is still paramount - if they're going to be affected in the way you want, so you need to understand the conventions and have internalised them, before you do something different. What's more, you'll only get the effect you're after if you know and keep the conventions most of the time except when you're bending them to deliberate purpose.
And to my mind there are no third-order rules. "Is it acceptable to change point-of-view in the middle of a scene," asks one newbie of another (Well, I hope they're newbies, otherwise this conversation is too depressing to contemplate) and continues: "Or am I not allowed to?" But allowed just doesn't come into it. These are not rules to be kept, or broken. Diktats such as not switching point-of-view, or "show don't tell", are someone's gross over-simplification of a rather subjective idea about what makes good writing. Often, yes, there's a kernel of some-of-the-time truth in the middle: "showing and telling" is a handy label for a very important tool, and head-hopping is a bad idea. But it's no accident that my Twelve Tools of Writing are mostly not about product - good writing on the page - but process: how to set things up so good writing happens.
But my blood pressure reaches dangerous heights when I hear "cut everything that has was in it" or the same for had. And when I heard of a computer program to search out words ending in -ly because we absolutely know that adverbs are totally forbidden don't we, I didn't know whether to laugh or cry. These are not rules. They're not even tools, because they're only tangentially related to what they're legislating about. They are nonsense, and they have pernicious effects on people's writing.
I'm all for writers being humble about what they don't know and can't (yet) do: God knows there's so much I don't understand and can't do in writing. But being humble about our incapacities, and yet arrogant enough to reject crap "advice", let alone "laws", whoever's peddling them, is part of the necessary schizophrenia of the writer. So I'd suggest that next time someone tells you about what you should and shouldn't do with your prose, you start by trying to decide which order the "rule" belongs to: First-order Rules (keep), Second-order Rules (conventions to keep, some to keep or bend on purpose), Tools (useful concepts), and Nonsense.