Which literary work is often regarded as the cornerstone of modern literature?

The work often considered the cornerstone of modern literature is "Pride and Prejudice" by Jane Austen. This novel has had a profound impact on the literary landscape due to its exploration of themes such as social class, gender, and individuality. Austen's sharp wit, characterization, and narrative style have influenced countless writers and formed the basis for the development of the modern novel.

While "Sir Gawain and the Green Knight," "Things Fall Apart," and "Beowulf" are significant literary works in their own right, they belong to earlier literary traditions and do not encompass the same modern concerns found in "Pride and Prejudice." Understanding the nuances of character, society, and irony in Austen's writing marks a shift toward the complexities that define modern literature. This distinction is part of why her work is so highly regarded in the context of literary evolution.