Final answer:
The excerpt from the prologue of Romeo and Juliet foreshadows the outcome of the play.
Step-by-step explanation:
The purpose of the excerpt from the prologue of Romeo and Juliet is to foreshadow the outcome of the play. The passage talks about the 'death-mark'd love' of the main characters and highlights the 'continuance of their parents' rage'. It implies that the play will revolve around the destructive consequences of their love and the ongoing feud between their families.
Learn more about foreshadowing in literature