Answer:
Chaucer looks to describe John and Alisoun's differences because he's setting the plot about possible adultery. Chaucer makes John aware of what could happen due to his differences with his wife. The main difference between John and Alisoun is her age because she's so much younger than John.
Step-by-step explanation:
The Miller's Tale is the story about a carpenter, John, and his wife, Alisoun. To make extra money, John rents out a room in his house to a scholar named Nicholas, who is eager to sleep with Alisoun.