The present paper discusses the result of a research study involving a group of five-year-olds who had been informally exposed to a foreign language (English or German) for the previous three years in some nursery schools in the Autonomous Province of Trento, Italy. The study investigates the benefits of early sensitization to foreign languages in pupils’ abilities in terms of listening comprehension, communicative strategies and speech acts by introducing a systematic task-based procedure for data collection. The results suggest that after prolonged exposure to a new language almost all the participants were able to understand a story and physically respond to common commands. Moreover, some pupils were already trying to speak the language and showed interesting trends in the development of communicative strategies and speech acts. The study has important implications not only for preschool teaching practice but also for language teaching research in this field, as it highlights the importance of systematic data collection on preschoolers’ competence in foreign languages for elaborating data-driven methodologies.