Differences in word learning in children: bilingualism or linguistic experience?

The current study examines how monolingual children and bilingual children with languages that are orthotactically similar and dissimilar learn novel words depending on their characteristics. We contrasted word learning for words that violate or respect the orthotactic legality of bilinguals' languages investigating the impact of the similarity between those two languages. In Experiment 1, three groups of children around the age of 12 were tested: monolinguals, Spanish-Basque bilinguals (orthotactically dissimilar languages), and Spanish-Catalan bilinguals (orthotactically similar languages). After an initial word-learning phase, they were tested in a recognition task. While Spanish monolinguals and Spanish-Catalan bilingual children recognized illegal words worse than legal words, Spanish-Basque bilingual children showed equal performance in learning illegal and legal patterns. In Experiment 2, a replication study was conducted with two new groups of Spanish-Basque children (one group with high Basque proficiency and one group with a lower proficiency) and results indicated that the effects were not driven by the proficiency in the second language, as a similar performance on legal and illegal patterns was observed in both groups. These findings suggest that word learning is not affected by bilingualism as such, but rather depends on the specific language combinations spoken by the bilinguals