Plausibility and grammatical agreement

Three experiments examined plausibility effects on the production and comprehension of subject–verb agreement. In a production task, participants were given a verb and sentence preamble and asked to create a complete passive sentence. The preambles contained two nouns (e.g., the album by the classical composers). The plausibility of the verb was manipulated so that either (a) both nouns could be plausible passive subjects (e.g., praised, as both albums and composers can plausibly be praised) or (b) only the head noun could be a plausible subject (e.g., played, as only albums can plausibly be played). The comprehension task was self-paced reading with the same materials. The results from both methodologies demonstrated robust plausibility effects. There were higher agreement error rates in production and longer RTs at the verb in comprehension when both nouns were plausible subjects than when only the head was plausible. Implications for current production models are considered and an alternative account is presented that is motivated by current comprehension models and other recent production data.