How do authors use foils in literature?

Authors employ foils in literature primarily to highlight contrasting qualities between characters, a technique that serves to emphasize their distinct traits and personalities. By placing two characters in opposition, the author can draw attention to specific characteristics, motivations, and behaviors that one character possesses compared to the other. This contrast can enhance the reader's understanding of each character, making their individual traits more pronounced and providing deeper insights into their roles within the narrative.

For example, if one character is bold and aggressive while another is timid and reserved, the differences between them can illuminate not only their individual personalities but also the broader themes of courage and fear in the story. This dynamic keeps readers engaged and can add layers of meaning to character interactions and development throughout the plot.

The other choices do not accurately represent the primary function of foils in literature. While introducing new themes and creating humor can occur in stories, they are not the central purpose of using foils. Summarizing the main events of the plot does not relate to the contrast in character traits that foils provide. Thus, the emphasis on contrasting qualities forms the crux of how foils are effectively used by authors.