When linguistic input contains inconsistent use of grammatical forms, children produce these forms more consistently, a process called "regularization." Deaf children learning American Sign Language from parents who are non-native users of the language regularize their parents' inconsistent usages. In studies of artificial languages…

A battery of standardized language tests and control measures was administered to three groups of at-risk language learners -- internationally adopted children, deaf children with cochlear implants, and children with specific language impairment -- and to groups of second-language learners and typically developing monolingual children. All…