What are Mercutio and Benvolio discussing before Romeo appears in II.iv of Romeo and Juliet?
Mercutio is also demonstrating his never-ending ability to talk, talk, and talk. He is criticizing Benvolio for being quick to fight. He says Benvolio will fight for just about any reason, someone coughing, someone wearing their Easter outfit to early, or even having a hair too many or too few in their beard. This is pretty ironic because Benvolio throughout the play is the peace-maker. Mercutio's sarcasm and wit throughout this portion before Romeo arrives sets the audience up for his war of the wits with Romeo. This is important to note because had Mercutio not been so wrapped up in the sound of his own voice and easily prompted to fight himself, maybe there would have been time to talk things out with Tybalt before the fights ensued.
Act II, Scene 4 of Romeo and Juliet opens on a street in Verona. The two characters that we see when the scene begins are Benvolio and Meructio. They are talking to one another as they walk.
The topic that they are talking about is Tybalt, who is one of the Capulets and a cousin of Juliet. Tybalt has sent a letter to Romeo's house. In that letter, he has challenged Romeo to a fight. Benvolio and Mercutio are talking about how great of a fighter Tybalt is and how much trouble Romeo will be in if he tries to fight Tybalt.