The United States and Germany are two predominantly monolingual countries with a significant number of multilingual speakers. Previous research on multilingualism in children on the autism spectrum has found no adverse effects on children's language and communication development but often excluded children with complex communication needs or…

The overall pattern of vocabulary development is relatively similar across children learning different languages. However, there are considerable differences in the words known to individual children. Historically, this variability has been explained in terms of differences in the input. Here, we examine the alternate possibility that children's…