Dialogue—conversation between two or more people—is distinguished from regular text through the use of quotation marks. If a single speaker is quoted for more than one paragraph, place quotation marks at the beginning of the first paragraph, but do not close the quotes until the end of the Speaker's final paragraph. A change in speakers is signaled by beginning a new paragraph after each person speaks.
"Did you say something, Sammy?" "I said I quit." "I thought you did." "You didn't have to embarrass them." "It was they who were embarrassing us."
I started to say something that came out "Fiddle-de-doo." It's a saying of my grandmothers, and I know she would have been pleased. "I don't think you know what you're saying," Lengel said. "I know you don't," I said. "But I do." — John Updike, "A & P"