Unterrichtsfilm; Audio-visual aids (language teaching) ; Computer (Sprachunterricht) ; Computer (language teaching) ; CALL; E-learning; Mobile-assisted language learning; MALL ; Sprachandragogik; Volkshochschule; Adult language teaching ; ESP; English for academic purposes; EAP ; English as a second language; ESL; TESOL ; Self-directed learning; Autonomes Lernen; Self-teaching ; Lehrmaterial; Teaching material ; Kulturvergleich; Language and culture