Spoken language ; Category (theory of grammar) ; Discourse marker ; Spracherwerb und neurologische Entwicklung; Language acquisition and neurological development; Sprache und Denken (Ontogenese) ; Language and thought (ontogenesis) ; Cognitive development; Language acquisition and cognitive development ; Spracherwerb (lex.) ; Language acquisition (lex.) ; Vocabulary (language acquisition) ; Word classes ; Interjection ; Word (definition of) ; Word formation