Spanish indexing DOM, topicality, and the case hierarchy

The Spanish language is known for its widespread phenomenon of Differential Object Mark-
ing (DOM). A particularly interesting feature of DOM in contemporary Spanish relates to
the obligatory use of a double system of marking – a “flagging” preposition and an “indexing”
clitic (Haspelmath 2005) – in the domain of the full personal pronouns. The prepositional
marker goes back to the very beginnings of the language, whereas the cross-referencing
strategy, also called clitic doubling, is the product of a much later development, which join-
ing forces with the existing older form gave rise to the twice-marked pronouns. In this paper
I focus on the origin of Spanish indexing DOM and, through a careful examination of the
first contexts of use, I propose that the relevant notion of “topicality” implicated in the evo-
lution of indexing DOM is not animacy, but has to do with the role participants play in the
event structure and the organization of these roles into a topical case hierarchy (Givón 1976).