Final answer:
Toni Morrison uses hyperbole in the described passage to emphasize the extreme suffering of the character, which accentuates the theme of the enduring impact of trauma and hardships in the novel.
Step-by-step explanation:
The literary device Toni Morrison uses in the quote "Eighty-six days and done. Life was dead. Paul D beat her butt all day every day until there was not a whimper in her" is hyperbole. Hyperbole is a figure of speech that involves an exaggeration of ideas for the sake of emphasis. In this case, the exaggeration of the length of time and the intensity of the beatings serves to highlight the relentless and extensive nature of the suffering the character endures. This device effectively contributes to the theme of the psychological and physical toll of unending subjugation and hardships.
Literary devices like hyperbole engage readers by providing an intense and vivid portrayal of experiences beyond literal interpretations. The effect is to elicit a deeper emotional response from the reader and underscore the lasting impact of trauma and abuse. Hyperbole, in combination with other stylistic elements like repetition and figurative language, enables Morrison to construct a narrative that is both compelling and reflective of the characters' complex inner lives.