"Then get a place out of the city then, shit."
if that's dialogue then it's not bad writing, it's how the character talks.
I disagree.
The way how people talk most times is contrary to standard English. It's just the way how dialogue works. It's not an essay.
No, it's not an essay. And yes, spoken English (vernacular or conversational) does differ from proper, written English.
Your job as a writer, however, is to communicate the dialog to the actor. Proper placement of commas (and use of them to begin with) is part of that. They communicate pauses in speech patterns. They demonstrate the relationship of one word or clause to another. The same goes for other punctuation: it impacts how we read, and in turn how your actors deliver, the dialog.
The dialog must also be communicated to the actor so that it can be clearly communicated to the audience.
"When's the last time you got laid?" is vernacular English, "when's" being used to contract "when" and "is". That isn't something that adheres closely to the rules of proper grammar and syntax, but it does reflect conversational English and still keeps the idea clearly communicable.
It can get more complicated if you're trying to write for a specific dialect, using thickly-accented idioms. English with influences of Creole, Gullah, even some of the isolated Appalachian dialects are all examples of places where writing can get tricky. Punctuation still applies as a guide for reading and delivery.
