The central research question is how intensive exposure to the majority language at school affects the development of vocabulary. In a cross-sectional study with a longitudinal subsample follow-up, we investigated the development of vocabulary during the first four years at school, as vocabulary development is considered an important factor regarding bilingual children’s success at school. The sample consisted of 126 bilingual Russian/German-speaking children aged 6;0 to 10;11 years in Germany, who were tested for expressive and receptive vocabulary using a picture naming task. Our results show that while the majority language is acquired at an expected rate, the heritage language’s extensive vocabulary does not develop further over the course of primary school attendance. The overlap of the vocabularies increases. Additionally, the number of items that are named exclusively in the majority language increases, whereas the number of items that are named exclusively in the heritage language decreases.

The cross-disciplinary research project ‘SprabiPiKs’ (‘Sprachbildungsprofis in mehrsprachigen Kitas’) – ‘Language education professionals in multilingual ECEC institutions’ – investigates a number of components related to the quality of interactions in multilingual early childhood education and care (ECEC). The project closely examines the interplay between the quality of interactions and pedagogical orientations on multilingualism, competencies of the professionals, and the conditions in ECEC facilities as well as in their neighbourhoods. To address the complexity, the sample consists of six childcare centres and their professionals. The project’s data collection method consists of interviews and group discussions with the professionals, videography of verbal interactions, and questionnaires on the conditions in the facilities and the neighbourhood. The objective is to contribute significantly to the understanding of the complex quality pattern in ECEC institutions from both an intercultural-educational and a linguistic perspective. Moreover, the project’s findings can be informative to enhance the quality of interactions with respect to the diverse linguistic backgrounds of children.

How does vocabulary in the heritage language develop? Does the social environment of the community have an influence? This chapter presents empirical results regarding the development of expressive and receptive vocabulary in the heritage language and analyzes the effects of amount of exposure, use, socio-economic status, dominance, and community on the acquisition of vocabulary in the heritage language. A Russian-German and a Turkish-German speaking sample are compared: 211 children at the age of 6–10 years were tested with a standardized picture naming task in a cross-sectional design. The results show a good receptive mastery and a limited expressive command of vocabulary with large individual differences, and only a slight development in the timespan of four years. Between the communities we find systematic variation, which we attribute to social and pragmatic differences with moderator and mediator effects. Possible limitations of the results are discussed with respect to cross-linguistic test effects.