One of the most salient hallmarks of construction grammar is its approach to argument structure and coercion: rather than positing many different verb senses in the lexicon, the same lexical construction may freely interact with multiple argument structure constructions. This view has however been criticized from within the construction grammar movement for leading to overgeneration. This paper argues that this criticism falls flat for two reasons: (1) lexicalism, which is the alternative solution proposed by the critics, has already been proven to overgenerate itself, and (2) the argument of overgeneration becomes void if grammar is implemented as a problem-solving model rather than as a generative competence model; a claim that the paper substantiates through a computational operationalization of argument structure and coercion in Fluid Construction Grammar. The paper thus shows that the current debate on argument structure is hiding a much more fundamental rift between practitioners of construction grammar that touches upon the role of grammar itself.
