Paris waits outside for the majority of the scene, while Friar Lawrence talks with Juliet about how to fix the situation with her marrying Paris, when she is already married to Romeo.
Juliet begs her father for forgiveness, saying to him how she realizes she needs to follow his orders. She then "agrees" to marry paris. Capulet then changes the day of the wedding from thursday to tuesday, which is the next day.
Juliet is trying to decide whether to drink the potion that Friar Lawrence gave to her, or to use her dagger. she then decides to use the potion, but keeps the dagger with her, so her family will think she is dead.