Question: since the guests are masked how does tybalt recognize romeo?
Answer: Moving through the crowd, Tybalt hears and recognizes Romeo's voice. Realizing that there is a Montague present, Tybalt sends a servant to fetch his rapier. Capulet overhears Tybalt and reprimands him, telling him that Romeo is well regarded in Verona, and that he will not have the youth harmed at his feast.