Nothing Can Break the Mood Like Bad Dialogue

Nothing can break the mood of a piece of writing like bad dialogue. My students are miserable when they are reading an otherwise terrific story to the class and then hit a patch of dialogue that is so purple and expositional that it reads like something from a childhood play by the Gabor sisters. ... I can see the surprise on my students' faces, because the dialogue looked okay on paper, yet now it sounds as if it were poorly translated from their native Hindi.