Syntactic development; Morphological development; Morphologie (Spracherwerb) ; Syntax (Spracherwerb) ; Grammatical development ; Konzept (Spracherwerb) ; Concept (language acquisition) ; Category (language acquisition) ; Spracherwerb und neurologische Entwicklung; Language acquisition and neurological development; Sprache und Denken (Ontogenese) ; Language and thought (ontogenesis) ; Cognitive development; Language acquisition and cognitive development ; Gender ; Motivation (morph.) ; French