Louis Sachar shows us how to use dynamic dialogue to spice up characters and plot, like below:
"What'd you do?" one of the campers asked him.
At first Stanley didn't know what he meant.
"They sent you here for a reason."
"Oh," he realized. "I stole a pair of sneakers."
The other boys thought that was funny. Stanley wasn't sure why. Maybe because their crimes were a lot worse than stealing shoes.
5/6M give it a go.