Medieval Italian literature. His research, publication, and pedagogic interests in Italian involve the Duecento and Trecento, from Brunetto Latini to Petrarch; and focus on issue of authority, identity, intertextuality, and the changing status of the Italian vernacular. He has published widely on Dante's transformative rewritings of the Classical poets (especially Ovid and Virgil), as well as on Dante's language theory.
His current work involves: 1) the politics of authorial subjectivity in both Petrarch and Boccaccio, especially vis-à-vis their responses to Dante; 2) the construction of Italian literary genealogies tied to issues of cultural authority; 3) Franco-Italian literary/cultural inter-actions (13th–early 16th centuries); 4) the first-person voice in medieval Italian narrative and lyric; poetry and prose; 5) philology and literary theory.