AbstractIn this paper we provide a comprehensive picture of differential object marking in Catalan, focusing on both the empirical facts and their theoretical contribution. We support some important conclusions. First, Catalan differential object marking is quite a robust and widespread phenomenon, contrary to what prescriptive grammars assume. Second, we show that, from a formal perspective, Catalan differential object marking cannot be completely subsumed under hierarchical generalizations known asscales. The contribution of narrow syntax mechanisms and nominal structure is fundamental, supporting recent views byLópez (2012)or Ormazabal and Romero (2007,2010,2013a,b), a.o. Building on these works as well as on observations initially made byCornilescu (2000)andRodríguez-Mondoñedo (2007), a.o., we adopt an analysis under which canonical, animacy-based differential marking results from the presence of an additional (PERSON) feature, beyond Case. This structural make-up is not only at the core of differences marked objects exhibit from unmarked objects with a Case feature, but also derives the prominence of differential marking on (animates) under information-structure processes, in the high left (and right) periphery, in contexts of the type discussed by Escandell-Vidal (2007a,b,2009).