Sir Toby uses a metaphor and personification.
An example of a literary device in Scene 3 is used by Sir Toby in response to Olivia’s mourning over her brother.
He is using a metaphor. Olivia does not literally have a plague. She has just succumbed to grief. When he says care is “an enemy to life” he is saying that she should not worry so much, because it is not good for her. He is concerned because she is determined to keep mourning her brother and not live her own life. Olivia will not accept suitors and hardly leaves the house.
Another example of a literary device is the personification Toby uses when he is describing his clothing. He wants to enjoy himself, even if Olivia does not approve. He likes to party. When he is asked to confine himself to “within the modest limits of order,” he complains.
The personification is the description of the boots hanging themselves. When he says this, it is personification because boots cannot actually hang themselves by their laces. A boot is not a person. Personification is describing something nonhuman with human qualities.
Sir Toby’s colorful language adds humor and interest to the story. Shakespeare liked to use characters like Toby to create comic relief and give the audience a break from some of the more serious aspects of the plot. Although this play is not a tragedy, it does discuss issues like death and identity. Toby’s language and actions make things more fun.