Investigating vulnerabilities in grammatical processing of bilinguals

Published online: 20 Dec 2018Bilinguals show a large gap in their expressive-receptive abilities, in both languages. To date, most studies have examined lexical processing. The current study aimed to assess comprehension and production of verb agreement, i.e., grammatical processing, in bilinguals, and to examine the factors that might modulate them: exposure, age and language-specific morphological complexity. Twenty balanced Basque-Spanish bilinguals (10 adults and 10 children) were assessed on comprehension and production of subject-verb agreement in both languages and object-verb agreement in Basque. Twenty age-matched Spanish-dominant Basque-Spanish bilinguals were assessed in Spanish only. The results revealed a consistent gap in Basque in both children and adults, with an advantage for comprehension. In Spanish, a gap appeared in children only, with an advantage for production. The gap size did not vary with the amount of language exposure but with age and morphological complexity, suggesting that these factors modulate bilinguals’ grammatical processing.The authors acknowledge financial support from the H2020 Marie Skłodowska-Curie Actions (FP7-PEOPLE-2011-IOF) awarded to the first author, and from the Spanish Ministry of Economy and Competitiveness, through the Severo Ochoa Programme for Centres/Units of Excellence in R&D (SEV-2015-490) awarded to the Basque Centre on Cognition, Brain and Language. NK was funded by a Swiss National Science Foundation Research Fellowship P2GEP1 165307