Grammaticality as Kind: Ontology, Epistemology, and Empirical Pay-off

This paper argues that grammaticality is best understood as a homeostatic property-cluster (HPC) kind anchored in morphosyntactic form–meaning pairings and regimented by community practice. The framework distinguishes objective grammatical status – whether the community licenses a form–meaning pairing – from the subjective feeling of ungrammaticality, which integrates grammaticality with processing costs, social evaluation, and prescriptive norms. Drawing on contemporary metaphysics of science, we show how grammaticality exhibits the key features of HPC kinds: a cluster of co-occurring properties (morphosyntactic well-formedness, semantic compatibility, community entrenchment), homeostatic mechanisms that maintain cluster stability (language acquisition, repair strategies, sociolinguistic policing), and systematic projectability supporting inductive generalization. Processing constraints shape what patterns can be licensed through acquisition and transmission while also affecting how licensed patterns feel during comprehension. This analysis clarifies why grammaticality supports explanatory and inductive generalization despite surface variation and gradience. The HPC framework predicts which phenomena will pattern with grammaticality (morphosyntactic violations, semantic mismatches at the syntax-semantics interface) versus those that won’t (pure phonotactic violations, processing overload). By grounding grammaticality in both cognitive mechanisms and social practices, the account reconciles the apparent universality of particular constraints with the evident community-relativity of others. The framework has implications for methodology (validating judgment tasks while acknowledging their limits), theory (reconciling generative and usage-based evidence), and typology (predicting which “exotic” grammars can exist as stable linguistic systems).