LAUSR

Abstract Agreement has always posed a puzzle to both linguists and psycholinguists because, both cross-linguistically and intra-linguistically, grammatical biases and processing biases exhibit a seemingly capricious mixture of form regulation and semantic interference. English in particular is famous for the latter. This work explores the thesis that agreement in production is sensitive to the size of the morphological component of every language. To be precise, the idea is that the richer the morphology of a language, the greater the formal encapsulation of its agreement operations is likely to be. Conversely, the poorer the morphology the more semantic interference (agreement ad sensum) will be attested. Four completion studies carried out with two dialectal versions of Spanish and two dialectal versions of Portuguese support this thesis. Both versions of both languages differ in morphological strength: thus, whereas the Spanish spoken in the south of Spain is characterized by acute morphological erosion, the one spoken in the north preserves an intact morphology. The difference is even greater between European Portuguese and Brazilian Portuguese, whose profound morphological erosion is well-known. The tests show robust effects of the morphology in the predicted direction, with the two varieties with intact morphologies showing statistically less probability of semantic interfacing. These results provide important evidence to bear on the nature of agreement.