Final answer:
Geoffrey Chaucer authored "The Canterbury Tales" in Middle English, which is the form of English used from 1150 to 1500, bridging the gap between Old English and Early Modern English.
Step-by-step explanation:
Geoffrey Chaucer wrote "The Canterbury Tales" in Middle English, which was the form of English spoken from 1150 to 1500. This was after the Norman Conquest and represents the language of a transformative period in English literature and society. An example of Chaucer's Middle English from the Prologue of "The Canterbury Tales" reads:
"Whan that aprill with his shoures soote The droghte of march hath perced to the roote, And bathed every veyne in swich licour Of which vertu engendred is the flour; Whan zephirus eek with his sweete breeth Inspired hath in every holt and heeth"
Chaucer's work is pivotal as it captures the linguistic and cultural shifts of the time, marking a departure from the Old English period (450 to 1066 A.D.) and transitioning towards Early Modern English (1500 to 1690), a period which would see the works of William Shakespeare.