This study investigated whether language-specific syllable type frequency and complexity exerted cross-language influence on Spanish–English bilingual children’s acquisition of syllable structure.

We compared the accuracy of bilingual and monolingual children’s singleton coda and onset cluster productions from Spanish and English single words elicited via a picture-naming task. Task stimuli provided multiple opportunities to produce all possible singleton coda and onset cluster types in each language.

Ten typically developing Spanish–English bilingual children (ages: 2;01–4;08) completed the task in each language. Five Spanish and 12 English age-matched monolingual peers completed the same task in their respective languages. Data were analyzed using mixed effects logistic regression. Analyses compared bilinguals’ Spanish and English singleton coda and onset cluster production accuracy rates to those of monolinguals.

Our results indicate that interaction occurred in bilinguals’ syllable structure acquisition in both languages. Bilinguals’ acquisition of singleton codas was accelerated relative to monolinguals’ in Spanish. Furthermore, bilinguals’ acquisition of complex onsets was accelerated in both Spanish and English. Results did not suggest that bilinguals’ acquisition of English singleton codas was delayed.

This is the first study to show that exposure to patterns of linguistic complexity specific to each language can accelerate bilinguals’ acquisition of phonological structure in both languages.

Our findings demonstrate that cross-language differences in complexity influence how interaction appears during bilinguals’ phonological acquisition, and suggest further investigation regarding the influence of frequency.