Anaphora (Spracherwerb) ; Reference (language acquisition) ; Wortbedeutung (Spracherwerb) ; Bedeutungsentwicklung; Semantic development ; Spracherwerb und neurologische Entwicklung; Language acquisition and neurological development; Sprache und Denken (Ontogenese) ; Language and thought (ontogenesis) ; Cognitive development; Language acquisition and cognitive development ; Learnability (of language) ; Lernbarkeit (von Sprache) ; Spracherwerb (Theorie) ; Language acquisition (theory of) ; Poverty of the stimulus-argument; Theory (language acquisition) ; Spracherwerb (lex.) ; Language acquisition (lex.) ; Vocabulary (language acquisition)