This book synthesises research on very early language learning in pre-primary organised instruction settings such as kindergarten, nursery or afternoon classes. Using a framework of ecological development, it investigates the nested systems in which very young learners operate, the other agents involved in each of these systems and the influence these agents have on children's foreign language learning. It explores the ecosystems of the individual learner and their family, educational institutions, general social climate and language education policies, resulting in a holistic view of early language learning and the key transitions into and out of pre-primary formal instruction settings. This is the first book to gather research to date on very young learners in formal settings, offering a comprehensive state of the art to researchers and graduate students in early language learning, second language acquisition and early years pedagogy.