Why does Juliet cry out in Act 3, Scene 2 of Romeo and Juliet?
I'm sorry; I read the question as Act 3, Scene 2, but when I posted, it came up as Act 2, Scene 2 . So, this answer is for Act 3, scene 2.
In the opening soliloquy of Juliet, "night" and "black" are repeated, the foreshadowing of death/marriage. Nevertheless, this soliloquy begins the scene in an upbeat manner before e sad news of Tybalt's death and Romeo's banishment. After the Nurse enters wringing her hands, Juliet becomes disturbed as the Nurse says "Ah well-a-day! he's dead!" (l.20). Juliet thinks the she speaks of Romeo: Again this is foreshadowing and an example of the theme of miscommunication in the play. Juliet cries out,
O, break, my heart!.../To prison, eye, ne'er look on liberty!/Vile earth, to earth resign; end motion here;/And thou and romeo press one heavy bier!(ll.32-35)
These lines are also foreshadowing the tomb where Juliet will be placed and future action in the play. Finally, the Nurse says "Tybalt is gone and Romeo banished" and Juliet cries out "O God! did Romeo's hand shed Tybalt's blood?" as she realizes the tremendous implications this act will have upon both the Capulets and the Montagues. Dashed are the hopes of Friar Laurence that the marriage of Romeo and Juliet may bring together these two families. Even Juliet experiences ambivalent feelings for Romeo, first referring to him as "serpent heart, hid with a flowering face!...A damned saint, an honourable villain!"(ll.48,54) But, at last, she defends Romeo reasoning that if he had not killed Tybalt, Tybalt would have killed Romeo.
Juliet cries out saying, "Ay me!" in Act 2, Scene 2 of Romeo and Juliet out of both love and frustration. In fact, I think of it as a loud sigh instead of an actual "cry." Juliet, unaware that Romeo is watching, begins talking to herself. In so doing, she explains both her love for Romeo and her frustration. Her frustration, of course, revolves around Romeo's last name (Montague). She proceeds to give her famous "What's in a name?" speech, summarized nicely in the lines: "Deny thy father and refuse thy name! / Or, if thou wilt not, be but sworn my love, / And I'll no longer be a Capulet." Of course, in getting incredibly profound, one could say that Juliet's sigh is a wish that the undeniable and age-long feud between the Montague and Capulet families never existed.