One example of personification can be seen when we first meet Romeo in the very first scene. He is feeling brokenhearted because Rosaline is rejecting him and also feeling frustrated by love. He feels that love is a torturous emotion because everyone is swayed by love whether a person wants to be or not; it's as if love bends a person to its will. Romeo expresses this sentiment when he personifies love in the lines, "Alas that love, whose view is muffled still, / Should without eyes see pathways to his will!" (I.i.169-70). In these lines, love is being personified as a blind person that is capable of manipulating someone into falling in love and becoming brokenhearted. However, these lines are also an example of an allusion. An allusion is when an author refers to another person or event found in another piece of literature. These lines are a classic allusion to Cupid, the Roman god of erotic love. Cupid is always portrayed as blindfolded; hence, love being personified as blind is an allusion to Cupid.
Many similes and metaphors can be seen all throughout the play, especially in the first act. We especially see examples of similes and metaphors in the speech in which Romeo first sees Juliet. He compares her beauty to brightness, especially comparing it to a rich jewel, like a diamond, hanging against very dark skin, as we see in the line, "Like a rich jewel in an Ethiop's ear" (I.v.48). Since this line begins with the word like and compares Juliet to a jewel against dark skin, we see that it is a perfect example of a simile.
A metaphor can also be seen in this passage when he compares Juliet to a flaming torch in the very first line of this speech. Metaphors, like similes, are comparisons; the difference is that in a metaphor the comparison is much more direct, like saying she is something rather than she is like something. The line, "O, she doth teach the torches to burn bright!" is a perfect example of a metaphor because she can only teach flaming torches to burn brightly if she is a torch herself and burning even more brightly than the other torches.