This volume presents current development trends in German as a foreign and second language across three thematic areas: The first part focuses on the relevance of older and newer concepts from second language acquisition research for teaching practice. The second part integrates analyses of teaching materials concerning selected morphological, lexical, pragmatic, and cultural aspects. The conclusion features the presentation of two projects related to conducting a simulation game in China and to an interdisciplinary digital data corpus. The volume brings together the work of early-career researchers, DaF (German as a Foreign Language) educators, and guests from the Department of German as a Foreign Language at the Technical University of Berlin.