How do I prevent characters from sounding identical in dialogue

writers-hq:

On the first draft, don’t sweat it so much. Individual voices will start to come through the more you write and the more you get to know your story. 

But once you’ve got the measure of each character, start to think about: 

a) What they want in each scene (i.e.: What are they trying to accomplish? To persuade another character of their point of view? To manipulate another character? To admit they’re wrong? To avoid blame?) 

b) How their personality might affect their style of speech (i.e.: Are they uncertain and anxious? Are they confident? Are they trying to keep a secret? Are they low or high status in the scene? Do they splurge out all their thoughts or never say what they mean?)

Beyond that, think about SUBTEXT in dialogue. Few of us really say what we mean, and never is that more true in fiction. Sure, the reader might know what’s going on in a character’s head but dialogue often serves to provide red herrings or complicate the situation or layer up the conflict. What’s going on beneath the surface that might inform the way your characters speak to one another?

Also look at this amazing scene from American Beauty (yes yes, Kevin Spacey your faves are problematic but suspend that for a moment because we’re talking about the WRITING here): https://youtu.be/ED7_y4jETo0

Each character has a distinctive way of speaking and getting their point across: 

Lester is dry and obviously trying to hold onto his frustration, making his dialogue stilted and short – until he blows his top. His dialogue is mainly focused on the asparagus but we know that’s not what he’s really talking about. 

Carol is sarcastic, borderline hysterical and talks A LOT – braindumping all her anger onto her husband. She’s almost talking to herself in this scene, in a way that makes us suspect she feels like no one ever listens to her. 

And Jane is quiet, insecure, and mumbles most of her dialogue. She does not want to be in the middle of this argument, and no one pays much attention to her at all. We get a palpable sense of her discomfort and feel sympathetic for her even though she barely says more than a few lines. 

Each voice is unique and each character is demonstrating their underlying desires and feelings sithout necessarily saying them out loud. 

On a sidenote: relying too much on dialect and accent and voice ‘quirks’ can be a lazy way of trying to differentiate characters. That said, some characters may well have certain speech patterns that help to both distinguish them from the other characters and reinforce the way they think/express themselves. For example, compare Granny Weatherwax and Nanny Ogg from Terry Pratchett’s witches series. Granny is all passive aggression and carefully chosen words while Nanny is a motormouth who says what she thinks and naturally puts people at their ease (often as a way of getting information out of them that they’d be too scared to tell Granny). The quirks of each are subtle but super effective. 

Hope that helps. Good luck!