Word class frequency ; Picture-book (function in language acquisition) ; Baby talk; Motherese; Child-directed speech; Ammensprache; Babysprache; Infant-directed speech; Fatherese; Language spoken to children ; Triggering (language acquisition) ; Language exposure (language acquisition) ; Input hypothesis; Input (language acquisition) ; Repetition (language acquisition) ; Spracherwerb (lex.) ; Language acquisition (lex.) ; Vocabulary (language acquisition) ; Word classes ; English (American) ; USA (English language in the) ; USA (engl. Sprache in den) ; English in the USA; Englisch in den USA; American English