How does this example of dramatic irony manipulate the audience sympathies, develops character, and develops the conflict and/or theme of the play.
The example is, Claudius thinks that nobody knows that he killed King Hamlet, but the Ghost told Hamlet that Claudius killed his father, and so the audience and Hamlet know that he did.
The fact that the audience knows that Claudius did in fact kill King Hamlet makes the audience feel sympathy for Prince Hamlet, but it also makes us question his actions or lack of actions throughout the play. The fact that the ghost tells Hamlet that he was killed by Claudius doesn't necessarily set up the dramatic irony in the play because Hamlet is not sure if the ghost is really his father or if the ghost is an evil spirit that is there to pull him into Hell. In act II scene ii Hamlet is expresses the fact that he is upset with himself after the player performs the monologue about Priam and Hecuba and begins to cry. Hamlet is having a hard time understanding how the actor can show so much emotion over someone he doesn't even know, but he has not done anything to avenge his father. However, Hamlet also states that he needs more proof that the ghost is telling the truth because he is still not sure that the ghost isn't evil. He states that he will use the play "to capture the conscious of the king" (II.ii.586). In other words he will watch Claudius's reaction and decide if he is guilty. Therefore, at this point we don't know for sure that Claudius is the killer.
However, in act III scene iii Claudius admits his guilt in a soliloquy when he tries to pray. He also says that his prayers will not go to Heaven because there is no action behind them. In other words he is not willing to give back the queen, the crown or his power -all things he obtained after the murder. The fact that we, the audience, now know that he is guilty but not willing to give back what he has received helps us to understand what an evil person Claudius really is and how much he deserves to die.
The dramatic irony also helps the reader understand why Hamlet is so quick to kill Polonius, who he thinks is Claudius, when he is talking to his mother and hears something behind the curtain (III.iv). The audience can understand why Hamlet wants to kill Clauidus. However, the dramatic irony also makes the audience wonder why Hamlet takes so long to get revenge. Hamlet gets upset with himself in his solioquy in act II scene ii and again in act IV scene iv because he has not avenged his father's death. Since the audience knows that Claudius did indeed kill King Hamlet, we are left to wonder why Hamlet just doesn't kill Claudius.