Error analysis ; Longitudinal study ; Komplexes System; Complex system; Emergenztheorie; Emergence (theory of) ; Systems theory ; Case study (second language acquisition) ; Zweitspracherwerb (lex.) ; Second language acquisition (lex.) ; Vocabulary (second language acquisition) ; Deviation (morph.) ; Complexity (synt.) ; English (American) ; USA (English language in the) ; USA (engl. Sprache in den) ; English in the USA; Englisch in den USA; American English ; Turkish