Metalinguistic awareness in L2 Italian children with a migrant background: A trade-off between cognitive advantages and syntactic vulnerabilities

Metalinguistic awareness is a domain where bilingual advantages have been reported, with bilinguals outperforming monolinguals in tasks that require separating syntactic form from semantic content, demonstrating higher selective attention, interference suppression, and inhibition skills ( Adesope et al., 2010 ). However, these cognitive advantages may be counterbalanced by weaknesses in specific linguistic domains, such as morphosyntactic processing. This study investigates the presence of such trade-offs in a Sentence-Judgment Task adapted from Bialystok (1986) in which monolinguals and bilinguals are compared in their ability to judge syntactically well-formed and ungrammatical utterances, regardless of their meaning. We assessed 80 school-aged children, including 36 Italian monolinguals and 44 bilinguals with Italian as a second language, using a task that involved 48 sentences varying in syntactic accuracy and semantic congruency across four conditions. Results from mixed-effects logistic regressions indicated that while both groups performed similarly when judging grammatical and semantically plausible sentences, bilinguals showed superior skills in evaluating syntactically correct but semantically anomalous sentences. Conversely, they underperformed in detecting grammatically incorrect but semantically plausible sentences, highlighting weaker morphosyntactic processing. These findings thus support the trade-off hypothesis ( Leivada et al., 2023 ), revealing that while bilinguals display cognitive advantages in metalinguistic awareness, they also may face challenges in linguistic domains. Importantly, this study addressed bilingual children with a migrant backgrounds, a population less studied and potentially more vulnerable, ultimately underscoring the importance of maintaining the home language and providing rich, high-quality input to enhance both their cognitive and linguistic development. • Bilingual children display an advantage inhibiting irrelevant semantic content, but were less precise detecting syntactic violations. • Trade-off mechanisms were observed as both advantages in metalinguistic awareness and linguistic difficulties were detected. • The advantage is found also in children with migrant background with low literacy in their home language. • Maintaining the home language is crucial for language and cognitive development.