Learning what 'can' and 'must' can and must mean

Annemarie van Dooren, Anouk Dieuleveut, Ailis Cournane, Valentine Hacquard

This corpus study investigates how children figure out that functional modals like must can express various flavors of modality. We examine how modality is expressed in speech to and by children, and find that the way speakers use modals may obscure their polysemy. Yet, children eventually figure it out. Our results suggest that some do before age 3. We show that while root and epistemic flavors are not equally well-represented in the input, there are robust correlations between flavor and aspect, which learners could exploit to discover modal polysemy.