Sir Capulet, Tybalt and Friar Lawrence, secondary characters but important and change the course of the play of Romeo and Juliet. The secondary characters of the play greatly contribute to the plot, character development and the themes of the play. The secondary characters are vital to the play.
Tybalt, Friar Lawrence and Capulet greatly contribute to the plot. Tybalt contributes to the plot by killing Mercutio. When Tybalt kills Mercutio it causes Romeo to retaliate and kill Tybalt, this results in Romeo being exiled from Verona when the prince arrives. Benvolio proves this when he speaks to the Prince upon his arrival, "Tybalt, here slain, whom Romeo's hand did slay." (III.i.160). Friar Lawrence contributes to the plot by sending Friar John to send the message of Juliet faking her death instead of Balthasar who is unaware that Juliet is not actually dead. Only Balthasar arrives who tells Romeo that Juliet is dead and Friar John does not arrive at all. Friar John explains to Friar Lawrence why he could not send the letter "I could not send it. Nor a messenger to bring it thee, so fearful they were of infection." (V.iii.14-16). Capulet contributes to the plot by throwing his party in which he hopes that Juliet and Paris will meet which allows Romeo to see Rosaline. Juliet instead meets and falls in love with Romeo. Capulet is speaking to Paris shortly before the party and says "This night I hold an accustomed feast, where to I have invited a many guest." (I.ii. 20-21). Therefore Capulet, Tybalt and Friar Lawrence all contribute to the plot of Romeo and Juliet. .
The secondary characters also contribute to the themes of the play. Tybalt contributes to the theme of love. Juliet greaves over Tybalt's death but she quickly gets over him once finding out that Romeo had took Tybalt's life. Juliet cries at the news of Tybalt's death but once she find out that it was Romeo that killed him she says, "That villain cousin would have killed my husband.