He had already indicated the sad conclusion of the play in the title: The Lamentable Tragedy of Romeo and Juliet.
reveal the plot, get the groundlings interested, and allow Shakespeare to compose a sonnet
Shakespeare didn't hold any grudges. He uses the phrase "ancient grudge" in the Prologue to Romeo and Juliet to describe the bad blood which was between the two families of Montague and Capulet.
So that the reader gets a good understanding and so they get hooked and want to read the book. For example, in Shakespeare's "Romeo and Juliet", the prologue briefly foreshadows what will happen, like the two feuding families trying to prevent Romeo and Juliet's love for one another.
The deaths of Romeo and Juliet
A prologue is a speech given before the start of the play. The person delivering the prologue speaks it directly to the audience and never interacts with anyone on stage. Shakespeare sometimes gave the prologue a name (he is the poet Gower in Pericles and the abstraction Rumour in Henry IV Part II) but the prologue is not a character in the play and is not acting a part. Shakespeare occasionally placed prologues at other places in the play. There are several in Henry V, one before Act 2 of Romeo and Juliet, and in A Winter's Tale (which has no prologue at the beginning) Time comes on in the middle and tells the audience that sixteen years have passed and that the baby the audience saw in the last act is now a grown woman.
Romeo and Juliet
Shakespeare uses the word "loins" to figuratively represent a person's private parts. In Romeo and Juliet, for example, he uses the word in the prologue to indicate that Romeo and Juliet are the children of long-time enemy families.
reveal the plot, get the groundlings interested, and allow Shakespeare to compose a sonnet
Either the witches predicitions in Macbeth or the prologue to Romeo and Juliet
No, "Romeo and Juliet" is a play by William Shakespeare and does not have a recurring chorus as in a song or music.
He gives an overview of the plot in the Prologue, but it is extremely vague and general. Most of it you could guess from the title: "The Lamentable Tragedy of Romeo and Juliet."
The prologue of Shakespeare's "Romeo and Juliet" states that the story ultimately results in the tragic ending of two families in Verona, the Capulets and the Montagues, consumed by their longstanding feud.
Shakespeare didn't hold any grudges. He uses the phrase "ancient grudge" in the Prologue to Romeo and Juliet to describe the bad blood which was between the two families of Montague and Capulet.
So that the reader gets a good understanding and so they get hooked and want to read the book. For example, in Shakespeare's "Romeo and Juliet", the prologue briefly foreshadows what will happen, like the two feuding families trying to prevent Romeo and Juliet's love for one another.
The deaths of Romeo and Juliet
A prologue is a speech given before the start of the play. The person delivering the prologue speaks it directly to the audience and never interacts with anyone on stage. Shakespeare sometimes gave the prologue a name (he is the poet Gower in Pericles and the abstraction Rumour in Henry IV Part II) but the prologue is not a character in the play and is not acting a part. Shakespeare occasionally placed prologues at other places in the play. There are several in Henry V, one before Act 2 of Romeo and Juliet, and in A Winter's Tale (which has no prologue at the beginning) Time comes on in the middle and tells the audience that sixteen years have passed and that the baby the audience saw in the last act is now a grown woman.
Many of Shakespeare's plays have prologues before Act 1: Romeo and Juliet, Henry V, Henry IV Part 2, and Pericles among them. You need to specify which play you are talking about.