Navigating languages: insights into the fundamentals of code-switching and its impact on dual language learning in preschoolers

The here presented dissertation set out to investigate the dual language learners’ habit to switch seemingly effortlessly between their languages during a conversation, referred to as code-switching. The objective of this dissertation was to analyze the evolution of specific code-switching behaviors over time, and to determine whether they reflect general linguistic and cognitive developmental processes or individual strengths and challenges in these areas. Moreover, this research aimed to investigate whether the broader socio-cultural environment would affect code-switching development beyond these individual linguistic and cognitive characteristics. Finally, the dissertation examined whether preschoolers’ code-switching could impact their further development of expressive language.
This work comprised three studies examining dual language learning preschoolers acquiring German or French as societal languages and Italian or Turkish as heritage languages. Code-switching behavior was assessed by introducing a novel parent-based code-switching questionnaire. Linguistic and cognitive control abilities were assessed through standardized and culturally-fair test instruments. By employing mixed method designs, relations between code-switching and individual characteristics, such as dual language abilities, were investigated cross-sectionally as well as longitudinally.
The findings derived from the three studies revealed preschoolers’ code-switching to represent a multifaceted phenomenon encompassing different underlying purposes (compensatory, overcoming linguistic gaps; preferential, language choice due to preference; pragmatic, as a communicative tool) and forms (intrasentential, within utterance; intersentential, between utterances). Over the preschool period only one developmental code-switching trend was identified. Namely, a tendency towards switches into the societal language, even in children with balanced language skills. Switches were shaped by preschoolers’ linguistic and cognitive strengths and challenges as well as the broader socio-cultural context. In addition, code-switching behavior itself influenced the development of children’s expressive societal language, likely, by prompting parental responses displaying language teaching.
By contributing to the understanding of code-switching behavior, its driving forces, and its potential impact on language development in young children, this dissertation may offer ways to use code-switching as a diagnostic and educational tool in the preschool context. At the end of this work, an integrative conclusion is offered that discusses the implications for research and practice.