One of the best ways to improve your dialog is to read it out loud. We know how normal speech sounds and our ears can pick up a clunker a mile away. Big words are usually the first fatalities--most of us don’t use them. Even if we know them, we don’t use them. Also we tend to use the simplest verbs. “We went to dinner.” Not, “We proceeded to dinner.” Generally when we speak we simplify and take short cuts. Another thing we do is use rhythm. There’s an up and down, rat-a-tat-tat to our exchanges. It comes naturally to us as humans. We expect it and respond to it. Our challenge as writers is to convey this with subtlety and without falling into sing-song verse. This is where reading our work out loud can help. Whenever I give readings I find myself ruthlessly editing. I can’t say fancy stuff out loud. It has to be plain and real. When I’m reciting dialog anything that sounds the slightest bit “writerly” makes me cringe. Reading bad dialog out loud is like exposing a vampire to daylight: pretty soon there’s something dead on the street.