Second language acquisition (language teaching) ; Zweitspracherwerb (Unterricht) ; Foreign language teaching ; Lernmotivation; Affekt (Einfluss auf Zweitspracherwerb) ; Affect (influence on second language acquisition) ; Motivation research ; Second language acquisition (pragm.) ; Zweitspracherwerb (pragm.) ; Interactionist hypothesis (second language acquisition) ; Conversational analysis (second language acquisition) ; English