The variety of Chaucer's tales shows the breadth of his skill and his familiarity with countless rhetorical forms and linguistic styles. Medieval schools of rhetoric at the time encouraged such diversity, dividing literature (as Virgil suggests) into high, middle, and low styles as measured by the density of rhetorical forms and vocabulary. Another popular method of division came from St. Augustine, who focused more on audience response and less on subject matter (a Virgilian concern). Augustine divided literature into "majestic persuades", "temperate pleases", and "subdued teaches". Writers were encouraged to write in a way that kept in mind the speaker, subject, audience, purpose, manner, and occasion. Chaucer moves freely between all of these styles, showing favouritism to none. He not only considers the readers of his work as an audience, but the other pilgrims within the story as well, creating a multi-layered rhetorical puzzle of ambiguities. Chaucer's work thus far surpasses the ability of any single medieval theory to uncover.
With this Chaucer avoids targeting any specific audience or social class of readers, focusing instead on the characters of the story and writing their tales with a skill proportional to their social status and learning. However, even the lowest characters, such as the Miller, show surprising rhetorical ability, although their subject matter is more lowbrow. Vocabulary also plays an important part, as those of the higher classes refer to a woman as a "lady", while the lower classes use the word "wenche", with no exceptions. At times the same word will mean entirely different things between classes. The word "pitee", for example, is a noble concept to the upper classes, while in the Merchant's Tale it refers to sexual intercourse. Again, however, tales such as the Nun's Priest's Tale show surprising skill with words among the lower classes of the group, while the Knight's Tale is at times extremely simple.
Chaucer uses the same meter throughout almost all of his tales, with the exception of Sir Thopas and his prose tales. It is a decasyllable line, probably borrowed from French and Italian forms, with riding rhyme and, occasionally, a caesura in the middle of a line. His meter would later develop into the heroic meter of the 15th and 16th centuries and is an ancestor of iambic pentameter. He avoids allowing couplets to become too prominent in the poem, and four of the tales (the Man of Law's, Clerk's, Prioress', and Second Nun's) use rhyme royal.