Transitioning developmental paths in modal flavors

Abstract This study investigates the cognitive plausibility of diachronic modal development using an experimental approach grounded in the Human Diachronic Simulation Paradigm, which has been proposed and shown to successfully simulate the conditions under which an attested semantic change occurs ( Gergel, 2020 ; Gergel et al. 2021 ). Building on historical claims that modal meanings evolve along a unidirectional path — from dynamic to deontic to epistemic meaning — we designed acceptability judgment experiments to test whether speakers accommodate hypothetical shifts in modal usage. Experiment 1 employed constructed stimuli, and Experiment 2 used naturally occurring sentences from the Corpus of Contemporary American English, testing three English modal expressions ( be able to, be allowed to, might ) across dynamic, deontic, and epistemic contexts. Results largely align with historical predictions (but there is also a notable exception that we discuss in more detail): be able to is acceptable in dynamic and deontic contexts but not epistemic; be allowed to remains strongly deontic and resists epistemic reinterpretation; might is highly acceptable in epistemic contexts and degraded elsewhere. A third experiment examined whether possibility adverbials facilitate the deontic-to-epistemic shift, revealing an interaction effect that reduces markedness in epistemic contexts. These findings support the experimental replication of diachronic tendencies while highlighting constraints on semantic change and the potential role of bridging elements. We conclude that experimental paradigms can illuminate mechanisms underlying language change and propose directions for future research integrating syntactic factors and contextual triggers.