Second language acquisition (language teaching) ; Zweitspracherwerb (Unterricht) ; Foreign language teaching ; Textbook analysis ; Begrüssungsformeln; Wishes; Wunschformeln; Greetings ; Second language acquisition (pragm.) ; Zweitspracherwerb (pragm.) ; Interactionist hypothesis (second language acquisition) ; Conversational analysis (second language acquisition) ; English ; Japanese