English as a second language; ESL; TESOL ; Lernmotivation; Affekt (Einfluss auf Zweitspracherwerb) ; Affect (influence on second language acquisition) ; Motivation research ; Role play (language teaching) ; Wortschatz (Sprachunterricht) ; Lernwortschatz; Vocabulary teaching ; Avatar; Massively Multiplayer Online Role-Playing Game; MMORPG ; Role play (pragm.) ; E-Mail; Voice mail; Chat; Computer-mediated communication ; Play (communication situation) ; Repertoire (linguistic) ; Quersprachigkeit; Linguistic repertoire ; Second language acquisition (pragm.) ; Zweitspracherwerb (pragm.) ; Interactionist hypothesis (second language acquisition) ; Conversational analysis (second language acquisition) ; English