Verbal irony (also called sarcasm) -- a writer makes a statement in which the actual meaning differs from the meaning that the words appear to express.
Situational irony -- accidental events occur that seem oddly appropriate, such as the poetic justice of a TV weather presenter getting caught in a surprise rainstorm.
Dramatic irony -- a narrative in which the reader knows something about present or future circumstances that a character in the story does not know.
