Notice that the last two lines of this scene end in a rhyming couplet. This rhyme signals to the audience and the stage hands that the scene has come to an end. Couplets were used to provide closure to a poem or resolve an exchange. In this couplet, Benvolio gets the last word and directly contradicts Romeo's statement that no one can turn his head. The order of this rhyme suggests that Benvolio is right and Romeo is wrong, and foreshadows Romeo and Juliet's meeting.
Notice that taking one's virginity and taking one's life here are viewed as the same thing. In a story about tragic love that ends in the lover's death, this is an interesting place to start the story. This rude play on words becomes a fitting way to foreshadow the ending and problematize the love that this play will depict before we have even met the couple.
In this context, "forfeit" means a misdeed, crime, or transgression, generally undertaken with the intention of causing injury. Romeo's statement is surprisingly accurate. He predicts that the course of the night's events will cause his untimely death. Much like the prologue, this statement interrupts the comedic exchange between Romeo and his friends to remind the audience how this story will end. Perhaps this is a way in which Shakespeare reminds the audience to pay close attention to the next scene.
To "have a bout" is to dance with you. Capulet here directly addresses the gentlemen in the room entreating them to dance. This demonstrates Capulet's misogynistic view of both relationships between the sexes and courtship and foreshadows his negative reaction to Juliet defying his wishes.
Mercutio uses this catalogue of tragic love stories to mock Romeo and his romantic feelings. However, this catalogue also works to remind the astute reader (or audience member) that Romeo and Juliet belong in this list. Mercutio's mockery inadvertently serves as foreshadowing for the end of the play.
Mercutio seems to be looking for a fight. He understands Tybalt's letter to Romeo as a challenge to his on life. Benvolio quickly corrects him by saying that Romeo will answer the challenge, not Mercutio. This hot headed response foreshadows Mercutio's later actions with Tybalt.
"Heralds" means messengers. Here, Juliet unintentionally touches on one of the themes presented in the previous scene: there are too many messengers, or people intervening, in Romeo and Juliet's love. This is also foreshadowing as their reliance on messengers will eventually lead to the tragic end of the story.
"begins the woe others must end...."See in text(Act III - Scene I)
With this line Romeo marks the turning point in the play and within himself. Thus far, the audience has seen Romeo melancholic and in love. This marks the point at which Romeo enters the feud. Ironically, Romeo acknowledges that this turn in events will end in woe, foreshadowing his tragic end.
"Grave man" means both someone who is serious and someone who inhabits a grave. As he dies, Mercutio continues to play with language. However, the double entendre now invoked by his speech is not playful but heavy, and foreshadows his own death.
Depart here means to take leave, but it also grimly points to the second meaning of this word, to depart from the world or die. Benvolio warns Mercutio to leave the fight because too many people are watching, while his language signals to the audience that this fight will be the death of Mercutio.
"we shall not scape a brawl,..."See in text(Act III - Scene I)
This is another instance of foreshadowing that refers to the tragedy promised in the Prologue. Moments like this remind the audience that they are watching a tragedy so that they understand the irony in these exchanges, which would otherwise be seen as comedic.
Juliet foreshadows her reaction to Romeo's eventual death. Without him, she cannot be herself or anyone else. Juliet's identity has become inextricably linked to Romeo's identity. Here, Juliet inadvertently offers the audience an explanation for her coming suicide.
Juliet's claim here that she will kill herself foreshadows the end of the play. Since we know that the young lovers take their lives from the Prologue, we know that the Priest will either offer no remedy or his remedy will fail.
By this phrase Juliet means that Romeo, her life, will leave when they open the window. However, it also foreshadows the end of the play. The entrance of daylight and the separation of the lovers marks a final shift in the play: we have moved out of the world of comedy, romance, or love and are now solely in the world of tragedy.
