Tragic irony: Tragic irony occurs only in fiction. It is when the words or actions of a character contradict the real situation with the full knowledge of the spectators. For example: In Romeo and Juliet, Romeo mistakenly believes that Juliet has killed herself, so he poisons himself. Juliet awakens to find Romeo dead so she kills herself with his knife.
Dramatic Irony: In drama, this type of irony is when the spectator is given a piece of information that one or more of the characters are unaware of. For example: in Pygmalion, we know that Eliza is a prostitute, but the Higgins family does not.
Situational Irony: Situational irony is when there is a difference between the expected result and the actual result. Take for example this account of the attempted assassination of Ronald Reagan: As aides rushed to push Reagan into his car, the bullet ricocheted off the bullet-proof car, then hit the President in the chest, grazed a rib and lodged in his lung, just inches from his heart. The bullet proof car was intended to protect the president, but nearly caused his death by deflecting the bullet.