The relationship between bilingual exposure and vocabulary development

TLDR

The study examined how the amount of bilingual exposure relates to receptive and expressive vocabulary performance in 5‑year‑old Montreal children learning French and English simultaneously versus monolingual peers. Participants were matched on age, socioeconomic status, nonverbal cognition, and language status, and then varied in the degree of exposure to each language across a continuum of bilingual exposure levels. A strong, exposure‑dependent relationship emerged, with equal exposure yielding receptive vocabulary comparable to monolinguals but requiring greater exposure for expressive skills; no receptive‑vocabulary gap was observed, likely due to Montreal’s supportive environment and the linguistic similarity of French and English, and early versus late onset of bilingual exposure did not affect vocabulary outcomes.

Abstract

The relationship between amount of bilingual exposure and performance in receptive and expressive vocabulary in French and English was examined in 5-year-old Montreal children acquiring French and English simultaneously as well as in monolingual children. The children were equated on age, socio-economic status, nonverbal cognition, and on minority/majority language status (both languages have equal status), but differed in the amount of exposure they had received to each language spanning the continuum of bilingual exposure levels. A strong relationship was found between amount of exposure to a language and performance in that language. This relationship was different for receptive and expressive vocabulary. Children having been exposed to both languages equally scored comparably to monolingual children in receptive vocabulary, but greater exposure was required to match monolingual standards in expressive vocabulary. Contrary to many previous studies, the bilingual children were not found to exhibit a significant gap relative to monolingual children in receptive vocabulary. This was attributed to the favorable language-learning environment for French and English in Montreal and might also be related to the fact the two languages are fairly closely related. Children with early and late onset (before 6 months and after 20 months) of bilingual exposure who were equated on overall amount of exposure to each language did not differ significantly on any vocabulary measure.