Full edition for scientific use. To capture how learners holistically engage with their multilingualism, in this international survey study we introduce and validate the construct of multilingual engagement. This is conceptualised as a multidimensional construct that describes how learners make use of, reflect on, and relate affectively to their entire language repertoire and their multilingualism more broadly. To examine the potential antecedents and outcomes of multilingual engagement, the dataset also includes biodata information regarding learners' language repertoire, and scales addressing learners’ beliefs about multilingualism, their perceptions of teachers’ beliefs, and their classroom engagement. Our main sample included 162 secondary-school students from five different countries. The participants’ age ranged from 16 to 19. Participants reported a diverse linguistic repertoire across their home, educational, and broader language backgrounds.

The files are under embargo until 02.11.2027