The major point of interest of this study is the investigation of implicit foreign-language acquisition in children. To determine not only the possibilities but also the boundaries and limits of foreign-language acquisition in a context like watching subtitled television, the test involved vocabulary, morphology, and syntax. The study included children before and after formal learning of the first foreign language (French) was started at school. By choosing French and Danish as foreign languages (whereas the first language for all participants was Dutch), the effect of first- and foreign-language similarity could be investigated at the same time (Danish being more similar to Dutch). Finally, using different age groups may give insight into the development of children’s implicit language-acquisition capacities and could contribute to our understanding of the existence of the sensitive period for foreign-language acquisition.