What literary format does Chaucer use to portray English society?

Chaucer employs the frame narrative format in "The Canterbury Tales" to portray English society. This structure allows various characters from different social classes to share their stories while journeying together on a pilgrimage. Through their tales and interactions, Chaucer critiques social norms and highlights the complexities of human behavior, effectively capturing the diverse fabric of 14th-century English society.