Congratulations to PhD student Ailis Cournane for her just published article in the journal Language Acquisition! The title of the article is "In Search of L1 Evidence for Diachronic Reanalysis: Mapping Modal Verbs".
The lexical mapping of abstract functional words like modal verbs is an open problem in acquisition (e.g., Gleitman et al. 2005).
In diachronic linguistics it has been proposed that learner mapping
errors are responsible for innovations in the historical record (see Kiparsky 1974; Roberts & Roussou 2003,
among others). This suggests that child error patterns should be
consistent with historical changes. I studied the acquisition of modal
lexemes by flavor (e.g., ability, epistemic) in order to assess the
validity of this proposal in relation to the mapping problem. A
preference task and a sentence-repair task were designed to address the
question: Do children make structural mapping errors that, if left
unchecked, are compatible with the innovations we see in the historical
record (e.g., deontic > epistemic)? This study provides experimental
data on the acquisition of modal lexemes by flavor and some long-awaited
preliminary support for the hypothesis that child learners drive