 Time plays an important role in the language and plot of the play . Both Romeo and Juliet struggle to maintain an imaginary world void of time in the face of the harsh realities that surround them . For instance , when Romeo swears his love to Juliet by the moon , she protests " O swear not by the moon , th <unk> moon , / That monthly changes in her circled orb , / Lest that thy love prove likewise variable . " From the very beginning , the lovers are designated as " star @-@ cross 'd " referring to an <unk> belief associated with time . Stars were thought to control the fates of humanity , and as time passed , stars would move along their course in the sky , also charting the course of human lives below . Romeo speaks of a foreboding he feels in the stars ' movements early in the play , and when he learns of Juliet 's death , he defies the stars ' course for him . 
