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.
Juliet's line completes the iambic pentameter in Romeo's preceding line. "Give me my sin again you kiss by the book" makes a full line of iambic pentameter and completes the ABAB rhyme scheme beginning with line 112.
Notice that the Nurse interrupts a second sonnet from being created. The proceeding four lines make up a quatrain - four lines in a sonnet with an ABAB rhyme scheme - of a new sonnet. While the sonnets occurred in a metaphorical space that played with religious and Biblical authority, the Nurse's interruption signals a return to the real world in which parental authority rules the lovers and their rhetoric.
The first lines that Romeo and Juliet speak to each other make up a perfect sonnet, 14 lines of iambic pentameter with an alternating rhyme scheme that ends in a couplet. Beginning with Petrarch's sonnets to the unattainable Laura, the sonnet tradition signifies the quintessential expression of love in the Early Modern period. Romeo and Juliet's ability to speak a sonnet to each other the first time they meet symbolizes their real love for each other. Unlike Rosaline, whom Romeo loved from afar, Juliet is able to engage in his love.
Notice that Romeo's first speech about Juliet occurs in heroic couplets, a poetic form used by epic and narrative poetry. Heroic couplets give a sense of poetic closure or finality. The rhyme scheme of these lines suggests that Juliet's beauty is absolute and Romeo perceives his love for her as something complete or perfect.
The finals lines of this play mimic the structure of the end of a sonnet, an ABAB quatrain followed by a rhyming couplet. This could be read as a sense of closure in which the Prince offers the audience the story's moral. It would also be read as another instance in which a character tries to shape the story by adding their own narrative.
