Perfective auxiliation in Italo-Romance: The complementarity of historical and modern cross-dialectal evidence

This chapter examines the history of the perfect auxiliaries ‘be’ and ‘have’ and their interaction in a range of Italo‐Romance dialects, and sets them in the broader context of the historical evolution of the Romance languages as a whole. It also reviews the literature on this construction from Perlmutter’s initial work on unaccusativity down to more recent times. It shows how the study of modern and medieval dialects may complement each other as sources of evidence and thus allow us to draw a single coherent picture. The historical data is drawn from old Florentine and old Romanesco while for modern varieties there is a particular focus on the dialects of Agnone (Molise) and Picerno (a Gallo‐Italic colony in Lucania). The chapter also underscores the degree of variation in auxiliary systems at earlier stages of development and explores the effects of syntactic standardization in the modern context.