Discuss Chaucer as a modern poet.

Another important step toward modern literature that
Chaucer takes in The Canterbury Tales is his use of
irony.

Every writer is a product of his/her time, in one
way or another.  Chaucer reacts against the literature of
his time. 

In "The Pardoner's Tale," for instance, he takes
a didactic (preachy, or designed only to teach), allegorical form, and reverses it,
turns it upside down, so to speak.  He takes an often-told tale usually used to
didactically preach about the evils of greed, and turns it back on to the tellers
themselves. 

He does so by using the stock, usual
characters--death, drunkards, good-for-nothings--in the story itself, as so many others
did before him, but having the story told by a Pardoner that is himself greedy and
despicable and sly.  This makes the focus of the tale the Pardoner himself, rather than
the greedy drunkards in the tale.

This turns medieval,
didactic, church-oriented, mostly low-quality literature into brilliant
irony. 

That's Chaucer.  That's why he's still in the text
books.  That's why his works are a big step toward modern
literature.