Shakespeare builds tension in the play by having the witches mysteriously appear and dissapear. Through dramatic irony he is giving the audience more information about the witches then the characters. They are thinking whether to trust the witches or not, but we already know that they shouldn’t.
The witches in Shakespeare's "Macbeth" create tension by making predictions about the future, which keeps the audience interested. Besides, they represent the supernatural world, since people in those times believed in curses and witches. Thus, they have the power to appear and disappear, as well as to look real, although they are not. Finally, they speculate with the Macbeth and the audience's dismay, as they are as dark, fearful and horrible as the protagonist's soul.
