Parental language mixing and its association with language outcomes of children with (a suspicion of) Developmental Language Disorder

Multilingual children naturally encounter language mixing in their environment. Since children’s language development depends on their language input, and processing language mixing in the input may be cognitively demanding, the amount of parental language mixing could affect children’s language outcomes. This matter is also highly relevant for children with developmental language disorder (DLD), who face challenges with language processing and uptake. We hypothesize that these children’s language difficulties may amplify any negative relationships between parental language mixing and the language outcomes of children with DLD. Using a combination of questionnaires, day-long audio recordings, and Bayesian hypothesis testing, we examined parental language mixing and its relationship with Dutch vocabulary and grammar outcomes in thirty 3- to 6-year-old multilingual children with (a suspicion of) DLD in the Netherlands. Analyses were controlled for overall exposure to Dutch, children’s age and parents’ education level. Contrary to our hypothesis, we found a positive, albeit modest, association between parental language mixing and children’s Dutch language outcomes. This suggests that language mixing in the input may not hinder majority language development in children with DLD. Replication and further research are needed to understand the broader implications of parental language mixing for multilingual development in children with DLD, also regarding their minority language outcomes.