In Act 1, scene 1 of "Romeo and Juliet", there are themes like humor, regret, and self pity. Compare with the tragedy in the prologue.
The tragedy in the prologue is the description of the "ancient grudge" between two families that leads to the death of their own children. However, the tragic deaths didn't just happen at once - they weren't planned and are not a direct result of their parents' rage. As we learn through the reading of the play, many events conspired to lead Romeo and Juliet to committing suicide. More than the events, however, are the human feelings and behaviors of the characters that lead to them being foolish, hot-headed, and rash.
The humor in scene 1 is the joking between the two servants. After the tragedy of the prologue, it is a bit of comic relief. However, it also serves to demonstrate that this is not a clear cut case of good vs. evil. These are characters who have as much happiness in them as they do anger and hatred. The regret and self-pity, evident in the aftermath of the sword battle and in Romeo's complaints, help to foreshadow how these characters will be led, through their emotions, down the "fearful passage of their death-mark'd love" towards suicide. It also foreshadows the regret and self-pity their parents will feel upon their deaths.