How does Shakespeare use language to present Juliet?

One quality that makes Juliet remarkable is her use of language, as one would expect in a Shakespearean hero.
In Romeo and Juliet, we enter a world in which language is incredibly debased. Samson, Gregory, and Mercutio especially speak in vulgar terms, making joke after joke about rape and masturbation. Everything that comes out of their mouths seems designed to proclaim that the world is a dirty, bestial place. Even the Nurse offers this view. These are the people who create Juliet's sheltered world.
Romeo may be less base, but his use of language is filled with Petrarchan cliches. Metaphors construct a world for him that is more about being in love with oneself as a lover than about devoting oneself to the object of one's love.
Juliet does not fall into either of these traps. It is rather shocking how little figurative language she uses in her earliest speeches. Only when imagining Romeo in the stars does she seem to dabble in flights of fancy. She seeks to lock down what she thinks and feels and to ask Romeo to be authentic as well. The balcony scene is notable in this, as she insists that he not swear his love on cliched, changeable objects such as the moon.
Later, she does learn to equivocate with her mother when discussing Romeo. She can lie to her father and the Nurse about being willing to marry Paris, and she can conjure a horrible scene of the grave, but her language is very much grounded in the reality of her emotions and her determination to live her own life. As we see her develop through her speeches, it's possible to see in her an early version of As You Like It's Rosalind. Like Juliet, Rosalind seeks to teach Orlando to speak truly and to back up speech with action.