The most common dialogue mistake writers make is writing what people actually say. Real speech is full of filler, repetition, and half-finished thoughts. Read it on the page and it’s exhausting. Good fictional dialogue sounds natural without being real. It’s edited conversation — the illusion of speech, not a transcript. The function test Every line of dialogue should do at least one of these things: Reveal character Advance the plot Create or deepen conflict Deliver information the reader needs (carefully — this one tips into “on-the-nose” fast) If a line does none of these, it probably shouldn’t be there.