The most well-known apostrophe in William Shakespeare's "Romeo and Juliet" occurs in Act 2 Scene 2, in which Juliet asks the absent Romeo, "Wherefore art thou Romeo?" Because an apostrophe can be defined as any time a character speaks to a personified idea or anyone who is not present, there are several apostrophes in the play.
In "the balcony scene" of "Romeo and Juliet," one of the most commonly referenced scenes in theatre, Juliet is thinking aloud about Romeo. She expresses her frustration with the fact he is an enemy of her family by asking, "O Romeo, Romeo! wherefore art thou Romeo?" In this line, she asks why he is named Romeo when any other name would be less likely to offend her family, but she is not speaking directly to Romeo; instead, she is talking to herself or to the "idea" of Romeo.
Not to be mistaken for the punctuation mark, literary apostrophes occur when characters speak as if they are addressing someone, but do not have anyone to address; Romeo and Juliet is a play with many examples. It is common for these figures of speech to be lead by "O!" like in the example above. Sometimes, apostrophes occur as emotional exclamations, as in the case of Romeo's "I defy you, stars!" in Act 5. Although several characters in "Romeo and Juliet" have apostrophes, Juliet's are probably the most prominent; she addresses Fortune in Act 3 Scene 5, a vial in Act 4 Scene 3, and finally a dagger in Act 5 Scene 3.