Komplexes System; Complex system; Emergenztheorie; Emergence (theory of) ; Systems theory ; Word frequency effect (psycholing.) ; Versprecherhäufigkeit; Speech error rate; Frequency (psycholing.) ; Transfer (second language acquisition) ; Transfer (Zweitspracherwerb) ; Cross-linguistic influence (second language acquisition) ; Interference (second language acquisition) ; Schwierigkeit (Zweitspracherwerb) ; Difficulty (second language acquisition) ; Complexity (second language acquisition) ; Processability theory; Language comprehension (second language acquisition) ; Complexity (synt.)