Conflicting cues and competition in subject-verb agreement

Traditional theories of agreement production assume that verb agreement is an essentially syntactic process. However, recent work shows that agreement is subject to a variety of influences both syntactic and non-syntactic, which raises the question of how these different sources of information are integrated during agreement production. We propose an account of agreement production in which several information sources contribute activation to singular and plural verb forms. Conflict between cues leads to competition which can in turn magnify the influence of subtle cues. Three fragment completion experiments tested key predictions of this constraint satisfaction approach. Experiment 1 demonstrated competition effects on verb choice and sentence initiation latencies. Experiments 2 and 3 demonstrated that conflicts between semantic and grammatical cues allow morphological regularity to exert a small but detectable effect on agreement. These results suggest that the constraint-satisfaction framework may provide a productive approach for understanding agreement production.