Every now and then I'm going to say shit that people are going to disagree with. This is probably going to be one of those things.
Just like with making places real. The way people talk makes them real. If someone leaves out the letter g a lot. As in leavin' or fuckin' you as a reader are going to see them in a different way, because you are attributing them with an accent based on the way they're talking. When you make such assumptions, some of the societal stereotypes built around people with the accent you have given this character will also become true.
But wait, there's more. Dialogue and back and forth can be used to paint scenes as well. Isn't that cool? Too often in writing, especially in class settings, people rely far too much on exposition. The big voice adjectives that tell us what everything looks like. There is not anything wrong with this approach. Almost all writers do this. Why not be different though? Take this semi-formed idea from this morning. The location isn't fully fleshed out, but you can see what I'm getting at. A better example, maybe after some food.
Fifty Bucks. He says. Fifty fucking dollars, Man. Didn't your fucking mother teach you to read. There is no more than fifty goddamned dollars in here. Not counting the penny cup, there. He points at the gun. Put that shit down. You won't kill me for a fucking video game and some fucking pennies.
Frank pushes the end of the thirty-eight further over the counter. The clerk looks at him, eyes traveling back and forth between the dark opening of the revolver and the dark holes in the center of Frank's eyes. The clerk, he smiles. It's not even loaded is it, you idiot shit? You don't think I don't have a Remington twelve gauge back here? Maybe I got a Smith & Wesson three-fifty-seven back here under the Swisher Sweets.
The clerk glances my way. He's not so smart is he? Did he even get you a gun? He's leaving you to the crows, Kid.
He thumbs the hammer back; says he's seen this shitty movie before. This asshole doesn't have shit back there. If he had firepower back there we wouldn't be having this talk. Besides, he isn't getting near enough money to shoot someone. I used to work at one of these slushy stands. Frank says this, laughing. They tell you to just give people the stupid money. Your life is worth more than what's in the store. Blah, blah, blah. Anyone willing to knock over a fucking glorified snack bar might be willing to put a few cents worth of lead into your face. It's all the same propaganda, Dude. It's all scare tactics. There's more than fifty bucks. They got a safe hidden behind that cigarette rack. The poster behind it never changes. Why? You aren't supposed to notice. Just hiding in plain sight. Right there is enough money from selling beef jerky to get us to Mexico.