In this play, Benvolio is flat character. He is sympathetic and kind person throughout the play, also a loyal and faithful associate to Romeo. Benvolio could have turned away the troubling situation of Romeo if he trusted this loyal friend. In fact, he is rational and calm in nature, always ready to defend Romeo and never changes. He is unbiased and trustworthy and neutral in his comments towards both families.
Juliet is a best example of dynamic and round character. Until she found Romeo, Juliet never cared for love or marriage. However, she falls in love with Romeo at first sight. One evening she has no desire of getting married and by the next evening she gets married, so keeps changing.