A tale of two Tagalogs

A well-received generalization in Tagalog is that only the argument that is cross-referenced by voice is eligible for A-bar extraction. However, recent work has shown that agents that are not cross-referenced by voice are also eligible. We provide naturally occurring data, along with experimental evidence, consistent with this more permissive picture. Further, we present computational evidence that participants were treating agent-extractions not cross-referenced by voice categorically, that is, they were either accepting or rejecting them in any given trial. Thus, we identify a piece of grammatical knowledge (i.e., extraction) that is systematic within an individual speaker but varies unpredictably across a population of Tagalog speakers. In other words, our data reveal two separable types of Tagalog speakers vis-à-vis extraction. We propose that this is a form of grammar competition that arises via the idea that the agent-first bias affects how child learners parse input strings under noisy conditions during acquisition.