Speech production (psycholing.) ; Critical period (language acquisition) ; Alter (Einfluss auf Spracherwerb) ; Age (influence on language acquisition) ; Age of acquisition; AoA; Sensitive period (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 ; Morbus Down; Mongolismus; Trisomie 21; Down's syndrome ; Complexity (synt.)