Unifying AGREE: How First Conjunct Agreement and Full Agreement can be Explained under a Single Operation

Previous research into Subject-Verb Agreement with Coordinated Phrase nominals (CoPs) has reported an agreement asymmetry. Subject-Verb constructions require full agreement (FA) with the Cop, whereas, Verb-Subject constructions allow First-Conjunct Agreement (FCA) or FA. Previous theories of FCA (Aoun et al 1994 and Johannessen 1996) fail to account for this structural effect under a unified operation of agreement (Munn 1999.) This paper will explore a different theory of FCA (suggested in lectures by Anders Holmberg), referencing the ‘coordinated structure constraint’ (CSC) (Ross 1967) and operation AGREE (Chomsky 2001), and test its predictions using grammaticality judgements. The idea is that FA results from the maximal CoP being established as Tense’s feature-copying goal, during Tense’s search for phi-features. In contrast, FCA results from Tense establishing the first conjunct alone as its goal. The Extended Projection Principle then requires movement of the goal to Spec-TP or an inserted expletive pronoun to satisfy its subject requirement. This explains the structural difference as the CSC would be violated by movement of the first conjunct out of the CoP. This paper hypothesises that in English: 1. Pre-verbal CoPs will require FA. 2. Post-verbal CoPs will allow FA or FCA. 3. When displaying partial agreement, the verb’s phi-features will match the first conjunct. 4. These hypotheses will hold for interrogatives (AGREE occurs before movement.) Results support hypothesis 1 and 3. Hypothesis 2’s prediction that participants would perceive FCA as natural post-verbally and unnatural pre-verbally was supported. However, results conflicted with hypothesis 2’s prediction that FA would also be permissible postverbally. The present, CSC-based theory cannot explain this finding without an additional rule of an obligatory move for the CoP goal to Spec-TP. It is concluded that the CSC-based theory of FCA remains the most credible due to its ability to unify FA and FCA under a single operation.