Idiot savant; Savant ; Sprachperzeption/Sprachproduktion (Asymmetrie von) ; Language perception/language production (disparity in) ; Active vocabulary/passive vocabulary; Passive vocabulary; Disparity; Language production/language perception (disparity in) ; Kindersprache (pathol.) ; Child language (pathol.) ; Specific language impairment; SLI; Dysgrammatismus (Kindersprache) ; Dysgrammatism (child language) ; Handicapped language acquisition ; Kindersprache (Sprachverständnis) ; Children's comprehension of language; Language comprehension in children ; Case study (pathol.) ; Asperger's syndrome ; Second language acquisition in children; Kindlicher Zweitspracherwerb; Child second language acquisition ; German ; Bulgarian