This book describes the process of learning and acquiring a foreign language as a construction process. The concept of construction used here is much broader than that of the so-called radical constructivism, which has significantly influenced the foreign language didactics discussion in recent years. The underlying understanding of construction is based on cognitive processing processes and views language processing, understood as the foundation of language learning, as a complex construction process that requires support, both in its receptive and productive forms. If language learning is equated with language use, as is commonly done in second language acquisition research today, then language processing holds great significance. Considerable effort has been made in this book to present the complex processes of language processing in as understandable a manner as the subject allows. The book is not aimed at cognitive linguists or psycholinguists, but primarily at foreign language didacticians and practicing foreign language teachers. It seeks to familiarize them with insights that can provide new impulses for school foreign language learning, or to underpin foreign language didactic approaches that are already being tested in practice with theoretical insights, in order to give them the authority they currently lack.