Morphophonological and conceptual effects on Dutch subject-verb agreement

Language production theories differ in their assumptions about the information flow between levels. Serial models hypothesise that different types of information, such as conceptual factors and morphophonological make up, would have an effect at different points during the implementation of agreement and would, therefore, not interact. Constraint-based models, on the other hand, entail an interplay of these two types of factors. Here, we present data from an experiment designed to test whether a conceptual factor (notional number) interacts with a morphophonological factor (determiner number ambiguity) resulting in an increased number of subject-verb agreement errors in Dutch. Analyses showed main effects of both factors but no interaction. We also carried out simulations of one specific serial model for production of subject-verb number agreement, the Marking and Morphing model. Our simulations in Dutch yielded an excellent fit between the model and these data (as well as other previously collected data). In conclusion, our results argue in favour of independent processing of these two types of information during agreement production and, more specifically, offer support for the Marking and Morphing model.