What are examples of dramatic irony in Act 1 and 2 of Hamlet?
Dramatic irony results when the audience or readers possess information that the majority of characters are ignorant of: We know what they don't know.
In Act I.v, the Ghost of King Hamlet reveals to Hamlet that the King had been poisoned to death by Claudius who spread the story that his death was from a snake bite, a story believed to be true by everyone in Denmark. Dramatic irony occurs because Hamlet, the Ghost and we know the truth that Claudius murdered Hamlet's father. After this revelation, we sympathise with Hamlet and begin to hate Claudius: "Now Hamlet hear ... Now wears his crown."
At the end of Act I.v, Hamlet makes his two friends Horatio and Marcellus swear that they must not reveal what they have just seen and heard. We sympathise with Hamlet who has decided to "put an antic disposition on" (to pretend madness) to deceive the others and not reveal his true feelings or future plan of revenging his father's death. Dramatic irony results because only we and his friends Marcellus and Horatio know that he is only pretending to be mad.
In Act II.i, Ophelia reports to her father Polonius the strange behaviour of Hamlet. Polonius immediately concludes that Hamlet is 'madly in love' with Ophelia: "This is the very ecstasy of love" and that he has gone mad because she has obeyed his instruction in spurning Hamlet's love: "That hath made him mad." Dramatic irony results because only we and his friends know that Hamlet is only pretending to be mad.
When Hamlet met Polonius, he pretended that he didn't know him and acted madly. only the readers know that Hamlet was acting.