Learning style; Cognitive style ; Second language acquisition (pragm.) ; Zweitspracherwerb (pragm.) ; Interactionist hypothesis (second language acquisition) ; Conversational analysis (second language acquisition) ; Second language acquisition (psycholing.) ; Case study (second language acquisition) ; Vermeidungsstrategie (Zweitspracherwerb) ; Avoidance strategy (second language acquisition) ; Ersatzstrategie (Zweitspracherwerb) ; Compensatory strategy (second language acquisition) ; Speaker strategy (second language acquisition)