Language Exposure in Bilingual Toddlers: Performance on Nonword Repetition and Lexical Tasks

Purpose: The amount of language exposure is correlated with bilingual lexical development, but findings are mixed on how exposure relates to nonword repetition (NWR), a complex skill involving both short-term processing and long-term vocabulary knowledge. We extend previous work to a younger age group by investigating the role of exposure on NWR versus vocabulary, along with the effect of item construction and scoring. Method: Sixty typically developing children (ages 2;5-3;6 [years; months]) were assessed for NWR and receptive and expressive vocabulary. Participants ranged in amount of previous exposure to English and French from 0% to 100% and were tested in both languages if able to participate, even with very limited exposure (28 completed testing in both languages, 11 completed testing in English only, 21 completed testing in French only). Results: Correlational analyses showed moderate to strong associations between the amount of exposure and vocabulary in that language, whereas the relationship of exposure with NWR was weak or nonsignificant, depending on scoring method. NWR correlated with vocabulary in English only. Performance on NWR was affected by nonword length but unaffected by wordlikeness. Conclusions: NWR and vocabulary were differently related to language exposure. The underlying mechanisms of NWR at this age appeared mainly reliant on short-term processes, in contrast to long-term vocabulary knowledge.