Differences between The Decameron and The Canterbury Tales
First of all both works are written on the vernacular, that is, the local language spoken by ordinay people. In an age when most English chose French, the language used at court, or Latin, the "lingua franca" used by educated people, Chaucer decided to employ the language spoken by the commoners, which nobody had dared to do before him. However, Boccaccio's elaborate style remains consistent throughout his works, Chaucer took a great care that each pilgrim should use the language according to his or her social position, cultural level and education, so that it becomes a means of characterization. Moreover, by pretending to be one of the pilgrims, he added a further touch of realism to the whole work as, in the eyes of his contemporary readers, he became a credible eye-witness.
Secondly, both works are stricter in a frame narrative, that is, is a main introductory story that serves the purpose of setting the scene for shorter stories. The Decameron opens with the description of the plague that ravaged Florence in 1348, which even young men and three women escaped by fleeing to a villa outside the city. To pass the time pleasantly, each of them will tell a story for every one of the ten nights spent together. This framing devices is certainly similar to the Prologue in The Canterbury Tales, but while Boccaccio describes the effects of the epidemic on the society at length, Chaucer focuses his attention on the people, presenting each pilgrim in such a lively Ms detailed way they the prologue becomes a full-size portrait of medieval England. Moreover, Boccaccio's story-tellers all belong to the same upper class, whereas Chaucer's include representatives from all social conditions, including several members of the clergy.