I've been dealing with two different projects today -- very different projects. Different settings, subgenres, themes. Different target readers, different experience levels from two different writers.
But they have one thing in common.
They both rely heavily on dialect. And they tend to get the dialect right and wrong in much the same ways. So I thought it might be useful to give a quick overview on dialect.
First thing to remember is that when we're talking about dialect, we're talking about spoken language. Spoken language = dialogue. Right? So this means that your dialect is best confined to what comes between the quotation marks. On occasion, you might want to include some dialect in other parts of the narrative -- in interior monologue, for example. But as a general principle, it's best kept between the quotes.
There are three basic aspects to dialect: pronunciation, slang, and sentence structure. The first of these, pronunciation, is the weakest way to convey dialect in writing.
Let's look at an example. Let's take the word pen. Depending on where you live and your personal regional dialect, when you read that word, you'll "hear" it in different ways. Some folks will hear it as pin, some as pen, and some will hear something approximating an Italian demi-vowel: peh-un.
And that's okay. There's no reason in the world that a typical writer working with typical prose would need to worry about how the reader would pronounce a particular word. As long as meaning and context are clear, pronunciation doesn't matter. In fact, that's the beauty of written language. It allows us to comprehend each other without having to puzzle out accents.
Writers sometimes reach for dialectic spellings of words in order to signal something about the cadence of a character's speech. Caribbean pirate? Shiver me timbers, yer pirate might be a-sayin'. Got a Nazi headmistress? Ve haf vays off making you shmarter, she says vit a shmack off de rular.
If you're like most readers, your reading pace slowed while reading the italicized portions of the previous paragraph. This is because pronunciation cues like odd spellings or punctuation need to be translated out of that dialect as we read the words.
Let that sink in for a moment.
You put all that work into getting your spelling to signal a particular accent, and the reader will automatically translate it into their own personal dialect as they read. That translation process slows them down.
Do I need to elaborate any further than this? Perhaps I should instead refer to John Gardner's The Art of Fiction, in which he classifies these "oddities of imitation or spelling" as "amateur sins" which are "matters so obvious to the experienced reader or writer that they seem at first glance to have no place in a book for serious writers.... [C]lumsy errors of the kind I've been treating help show clearly what we mean when we speak of 'things that distract the reader's mind from the fictional dream,' and nothing in what I'm saying is more fundamental than the concept of the uninterrupted fictional dream."
In other words, your job is to lull the reader into forgetting that they're reading, and you can't do that if you continually call attention to the arrangement of the letters and punctuation marks on the page.
Enough about pronunciation, then.
If you want to use dialect to signal something about a character's background, much better to use vocabulary or sentence structure to do so. It's almost become a cliche to have a Scottish warlord talk about wee bairns and bonny lasses, but that's because it works: these terms are strongly associated with Scottish speech.
Ditto for the guru using Yoda-esque inversions, the Wooster-like Englishman with his "I say" and "By Jove," and the Frenchwoman who asks, "This hat is pretty, is it not?" Phrasings and word choices can signal as much about a character's dialect as any attempt to convey an accent.
I'm not advocating for cliches. Not at all. Instead I'm advocating that you listen to dialect for something more than pronunciation. Listen for different usages or slang terms, for different ways of organizing the parts of speech into coherent concepts. You can get away with a little bit of dialect-specific spelling here and there, but your writing will be much stronger if you avoid that in favor of other techniques.