Syntactic development; Morphological development; Morphologie (Spracherwerb) ; Syntax (Spracherwerb) ; Grammatical development ; Kindersprache (pathol.) ; Child language (pathol.) ; Specific language impairment; SLI; Dysgrammatismus (Kindersprache) ; Dysgrammatism (child language) ; Handicapped language acquisition ; Kindersprache (Sprachgedächtnis) ; Children's verbal memory; Verbal memory in children ; Kindersprache (Sprachverständnis) ; Children's comprehension of language; Language comprehension in children ; German ; English ; Swedish ; French ; Italian ; Spanish