Macbeth is a play which is full of confusion, surprise, and lies. This becomes clear via dramatic irony, which means that the audience knows something which the character does not because the playwright has made sure that our level of knowledge is greater.
One example is when King Duncan describes Macbeth’s castle as a pleasant place which is good for his nerves (1.6.1-3). This comes across as fairly ironic since we have just seen the Macbeths plotting to murder him in the previous scene. Duncan is ignorant of this and does not realize that he is already doomed by coming to their castle.
Another example is when Macduff tries to keep the horrible news of Duncan’s death from Lady Macbeth because “the repetition, in a woman’s ear, / Would murder...