English as a second language; ESL; TESOL ; Avatar; Massively Multiplayer Online Role-Playing Game; MMORPG ; Code-clustering; Bildlinguistik; Co-speech gesture; Embodiment (Kommunikationsforschung) ; Embodied interaction; Multimodal communication ; E-Mail; Voice mail; Chat; Computer-mediated communication ; Play (communication situation) ; English as international medium ; Second language acquisition (pragm.) ; Zweitspracherwerb (pragm.) ; Interactionist hypothesis (second language acquisition) ; Conversational analysis (second language acquisition) ; English