Interference (pragm.) ; Bitte; Request ; Child language (conversational analysis) ; Kindersprache (pragm.) ; Conversational analysis (child language) ; Second language acquisition (pragm.) ; Zweitspracherwerb (pragm.) ; Interactionist hypothesis (second language acquisition) ; Conversational analysis (second language acquisition) ; Third language acquisition ; Transfer (second language acquisition) ; Transfer (Zweitspracherwerb) ; Cross-linguistic influence (second language acquisition) ; Interference (second language acquisition) ; Second language acquisition in children; Kindlicher Zweitspracherwerb; Child second language acquisition ; English ; Catalan ; Spanish