two young children whispering


Bilingualism in children

How does one child acquire and use two different languages? Children who are raised bilingually usually know which language they should speak to a person and it is not always obvious that these children are bilingual.

However, there are noticeable differences between bilingual children and their monolingual peers. For example, ‘de beker van Sharon’ is a common Dutch expression, which could be literally translated as ‘the cup of Sharon’. Although this is not wrong, English native speakers would hardly ever use this expression. They would say ‘Sharon’s cup’. This is an example of the structure of one language being incorporated into another.

Influence of one language on the other

The aim of the 2in1 project is to examine how a bilingual child’s languages affect each other and the circumstances under which this occurs. Until now, this issue was primarily examined in bilingual adults. The project will also investigate whether the effect between languages is the same for all language combinations. And ask whether this depends on which two languages the child learns, which language is dominant in his/her environment, or how proficient the child is in both languages.

The project will focus on children between three and ten years of age, who are growing up in families where German, English, Greek or Turkish is spoken. The researchers are now also focusing on what happens after this age, specifically in adolescents and adults aged between 15 to 40 who have grown up speaking Dutch and German or Dutch and English.


  • Tsinivits, D. & Unsworth, S. (2020). The impact of older siblings on the language environment and language development of bilingual toddlers. Applied Psycholinguistics. DOI: [Open Access]
  • Van Wonderen, & Unsworth, S. (2020). Testing the validity of the Cross-Linguistic Lexical Task as a measure of language proficiency in bilingual children. Journal of Child Language. DOI: [Open Access]
  • Bosch, J. & Unsworth, S. (2020). Cross-linguistic influence in word order: Effects of age, dominance and surface overlap. Linguistic Approaches to Bilingualism. Pre-final version available here.
  • Van Dijk, C.N., van Wonderen, E., Koutamanis, E., Kootstra, G.J., Dijkstra, T., & Unsworth, S. (2021, accepted). Cross-linguistic influence in simultaneous bilingual children: a meta-analysis. Journal of Child Language.
  • Kletskoppen: Children’s Language Festival
  • Kletsheads: a podcast about multilingual children for parents, teachers and speech therapists.
  • Multilingualism in picturesShort animated clips on multilingualism for parents, teachers and children. Available in both English and Dutch.



Contact information

More information on this research study? Questions from the media may be directed to the science editor. All other questions may be directed to the researcher.

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