The Impact of the Spanish-to-English Proficiency Shift on the Grammaticality of English Learners.

Purpose The general aim of this study is to enhance our understanding of the patterns of language growth in Spanish and English during the school years. In this study, we used a longitudinal retrospective approach to explore the growth of the percentage of grammatical utterances (PGU) in both Spanish and English in 2 groups of English learners (ELs): ELs attending English-only instruction and ELs attending Spanish-English bilingual instruction. Method The participants included 1,080 ELs. ELs produced at least 3 story retells in both Spanish and English between kindergarten and 2nd grade. All stories were transcribed and coded for errors, and PGU was calculated for each story. Results At the onset of the study, children showed higher PGU in Spanish and lower PGU in English. Growth curve analysis indicated that PGU in English improved over time, whereas PGU in Spanish declined in both instructional groups. However, those children who were in bilingual programs showed a slower rate of decline in Spanish PGU and a slower rate of improvement in English PGU. By the age of 9 years, children in English-only programs had approximately a Spanish PGU of 65% in Spanish, whereas children in bilingual instruction had an average Spanish PGU of 80%. The improvement in English PGU was steady with a small difference in the rate of growth benefiting children in English-only programs. Conclusion The results of this study document a shift in language proficiency from Spanish to English during the school years. This study offers evidence of a temporary period of relatively low grammaticality in both languages that seems to be the result of a shift in proficiency from Spanish to English.