Final answer:
The three witches in Macbeth prophesy that Macbeth will be Thane of Cawdor and the king, while Banquo will be lesser than Macbeth yet greater, not so happy but happier, and will father a line of kings despite not being one himself.
Step-by-step explanation:
In Scene 3 of Shakespeare's Macbeth, the three witches make significant predictions for both Macbeth and Banquo. For Macbeth, they hail him as the Thane of Glamis, which he already is, as the Thane of Cawdor, and finally, as a future king. While Macbeth is initially skeptical, asking 'But how of Cawdor?' as the current Thane of Cawdor is alive and well, the witches' prophecy soon begins to unfold as reality.
Banquo, on the other hand, is told that he will be 'lesser than Macbeth, and greater,' 'not so happy, yet much happier,' and that he will 'father a line of kings' despite not being one himself. These cryptic messages set the stage for the unfolding drama. Banquo questions the truth of these prophecies but acknowledges their impact on Macbeth, observing his rapt attention and stating, 'Look, how our partner's rapt.'