* The Frame Story: This is the overarching structure of the narrative. The pilgrims are traveling to Canterbury and agree to tell stories to entertain themselves. This creates a framework within which the individual tales can be told.
* The Host's Role: The Host, Harry Bailey, acts as a sort of moderator, introducing each tale and sometimes offering commentary on the stories. He also keeps the pilgrims on track and ensures that the competition for the best story continues.
* Interwoven Themes: While each tale is independent, they often touch upon similar themes, such as love, morality, social hierarchy, and the nature of religion. This creates a sense of unity and allows the stories to resonate with each other.
* Interpersonal Relationships: The pilgrims interact with each other, both within the frame story and within the tales themselves. This adds a layer of complexity and realism to the narrative, and helps to create a sense of community among the characters.
* Humor and Irony: Chaucer uses humor and irony throughout the work to engage the reader and to comment on the characters and their stories. This also helps to hold the narrative together by creating a sense of shared experience between the reader and the characters.
* Language and Style: Chaucer uses a distinct and often humorous style of language, which helps to unify the tales and create a consistent tone.
In conclusion, Chaucer uses a multifaceted approach to hold the narrative of The Canterbury Tales together. The frame story, the Host's role, interwoven themes, interpersonal relationships, humor, irony, and language all contribute to the overall unity and cohesiveness of the work.