In the US, children who speak Spanish at home often begin learning English when they start school, and their dominant language shifts from Spanish to English over time. To get a better idea of how this happens, the authors of this study looked at the change in grammatical accuracy (percent grammatical utterances or PGU*) in Spanish and English narrative retells from kindergarten to second grade.
As expected, children’s PGU in English went up over time, while PGU in Spanish went down. The researchers compared children in bilingual (English–Spanish) vs. English-only classrooms. For children in bilingual classrooms, the decrease in Spanish PGU was slower, but the increase in English PGU was slightly slower also.
The researchers also looked at a subgroup of the children who had lower PGU in Spanish at the outset. They called this group “low grammaticality” because they didn’t have enough measures to confidently diagnose developmental language disorder (DLD). Children in this group showed a different pattern, with Spanish PGU holding steady for those in bilingual classrooms, suggesting that they benefited from bilingual teaching.
For a brief time (around age 8), English and Spanish PGU scores for the low grammaticality group looked similar to the rest of the children, which means that if we assessed them at this point, we might not be able to tell who does and doesn’t have DLD. The authors encourage us to assess children in their home language early on, before this shift happens.
So as if assessing English language learners wasn’t hard enough, we also need to consider the type of instruction children are getting and their skills in each language over time. Ideally, we’d assess children in their home language right when they start school. When that’s not possible, dynamic assessment might help us to differentiate language disorders from normal language dominance shifting during the early school years. For other resources on diagnosing DLD in English language learners, see reviews here, here, and here.
*Remember that higher PGU means more accurate use of grammar.
Castilla-Earls, A., Francis, D., Iglesias, A., & Davidson, K. (2019). The impact of the Spanish-to-English proficiency shift on the grammaticality of English learners. Journal of Speech, Language, and Hearing Research. doi: 10.1044/2018_JSLHR-L-18-0324.