Most studies on bilingual language development focus on children’s second language (L2). Here, we investigated first language (L1) development of Polish-English early migrant bilinguals in four domains: vocabulary, grammar, phonological processing, and discourse. We first compared Polish language skills between bilinguals and their Polish non-migrant monolingual peers, and then investigated the influence of the cumulative exposure to L1 and L2 on bilinguals’ performance. We then examined whether high exposure to L1 could possibly minimize the gap between monolinguals and bilinguals. We analyzed data from 233 typically developing children (88 bilingual and 145 monolingual) aged 4;0 to 7;5 (years;months) on six language measures in Polish: receptive vocabulary, productive vocabulary, receptive grammar, productive grammar (sentence repetition), phonological processing (non-word repetition), and discourse abilities (narration). Information about language exposure was obtained via parental questionnaires. For each language task, we analyzed the data from the subsample of bilinguals who had completed all the tasks in question and from monolinguals matched one-on-one to the bilingual group on age, SES (measured by years of mother’s education), gender, non-verbal IQ, and short-term memory. The bilingual children scored lower than monolinguals in all language domains, except discourse. The group differences were more pronounced on the productive tasks (vocabulary, grammar, and phonological processing) and moderate on the receptive tasks (vocabulary and grammar). L1 exposure correlated positively with the vocabulary size and phonological processing. Grammar scores were not related to the levels of L1 exposure, but were predicted by general cognitive abilities. L2 exposure negatively influenced productive grammar in L1, suggesting possible L2 transfer effects on L1 grammatical performance. Children’s narrative skills benefitted from exposure to two languages: both L1 and L2 exposure influenced story structure scores in L1. Importantly, we did not find any evidence (in any of the tasks in which the gap was present) that the performance gap between monolinguals and bilinguals could be fully closed with high amounts of L1 input.

Reading and telling stories to children improves their narrative skills, which is well-documented for monolinguals, but not for bilinguals. We investigated whether bilingual narratives improve when the child is provided with a model story. We studied the narratives of Polish-English bilingual children (n = 75, mean age 5;7 years; months) raised in the UK. We elicited narratives through picture stories in two modes: told spontaneously and retold after a model provided by an adult experimenter. The bilinguals told and retold stories in Polish and English. The study combined a within-subject design, comparing the bilinguals' two languages, and a between-subject design, comparing the stories told and retold in Polish by the bilinguals and by Polish age-matched monolinguals (n = 75). We investigated whether retelling might improve bilingual and monolingual storytelling to the same extent. In the stories, we assessed both the macrostructure (e.g. story structure and answered comprehension questions) and microstructure (e.g. type-token ratio). We found a positive effect of retelling for the macrostructure in both monolinguals and bilinguals (regardless of the language). As for the microstructure, when retelling, children told longer stories, regardless of the language (Polish, English) and group (bilingual, monolingual). We argue that retelling stories improves the narrative skills of bilinguals. ARTICLE HISTORY

The ability to recursively infer the mental states of others to explain their complex behavior in ambiguous social situation may be called Advanced Theory of Mind (aToM). The relations between two components of aToM, cognitive and affective, measured on a behavioral level in 151 Polish 13-year-olds and 174 16-year-olds was examined. The role of age, gender and friendship style and its relations to the cognitive and affective aToM was explored. Cognitive aToM was only weakly to moderately related to affective aToM. Across both age groups females scored higher than males. Males' aToM abilities did not differ according to age, but they scored higher in the cognitive aToM than affective ToM. Also, different aspects of friendship style were significant predictors of both aToM abilities. The implications for two aToM components within a gendered social context were discussed.