Please provide three good reasons why Tybalt is the antagonist in Romeo and Juliet.
1. An antagonist is the person who opposes the protagonist in some way; the antagonist can even be the protagonist's adversary. Tybalt is certainly the one who most opposes Romeo. He becomes irate that Romeo dares to show up at Lord Capulet's party, even when Lord Capulet says that he's heard that Romeo is a pretty good kid and that Tybalt should "take no note of him." Regardless of his uncle's wiser, calmer words, Tybalt remains enraged at what he perceives as Romeo's audacity.
2. Then, the next day, Tybalt challenges Romeo to a fight, a move that definitely positions him as Romeo's adversary. Though Romeo first refuses, when Tybalt kills Mercutio, Romeo becomes enraged and kills Tybalt. This results in Romeo's banishment from Verona, an event that makes it quite difficult for the pair to be together.
3. It is Tybalt's death, then, that causes Lord Capulet to change his mind about marrying Juliet to Count Paris at her age. He decides, in order to pull her from what he thinks is her terrible grief over her cousin, that Juliet and Paris should be married immediately. This is what results in Juliet's desperation and the plan for her to fake her own death.
Therefore, without Tybalt's opposition to Romeo, his positioning of himself as Romeo's adversary, and then his violent death, the result of the fight to which he challenged Romeo, it is possible that this play would not have ended with such tragedy.