The acquisition of verb morphology is often studied using categorical criteria for determining the productivity of a morpheme. Applying this approach to Japanese, an agglutinative language, this study finds no consistent order for morpheme acquisition and that productivity could be explained by sampling effects. To examine morpheme acquisition…

This study tested the claim of input-based accounts of language acquisition that children's inflectional errors reflect competition between different forms of the same verb in memory. In order to distinguish this claim from the claim that inflectional errors reflect the use of a morphosyntactic default, we focused on the Japanese verb system,…

To explain the phenomenon that certain English verbs resist passivization (e.g., "*£5 was cost by the book"), Pinker (1989) proposed a semantic constraint on the passive in the adult grammar: The greater the extent to which a verb denotes an action where a patient is affected or acted upon, the greater the extent to which it is…

Many generativist accounts (e.g., Wexler, 1998) argue for very early knowledge of inflection on the basis of very low rates of person/number marking errors in young children's speech. However, studies of Spanish (Aguado-Orea & Pine, 2015) and Brazilian Portuguese (Rubino & Pine, 1998) have revealed that these low overall error rates…