Ambiguity (theory of grammar) ; Ambiguität (Grammatiktheorie) ; Principles and parameters theory; Prinzipien- und Parametermodell; Parametrization ; Category (theory of grammar) ; Sprachpsychologie; Psycholinguistics ; Interimsgrammatik (Spracherwerb) ; Lernervarietät (Spracherwerb) ; Learner variety (language acquisition) ; Interlanguage (language acquisition) ; Minimalist program; Generative theory of language ; Second language acquisition (psycholing.) ; Transfer (second language acquisition) ; Transfer (Zweitspracherwerb) ; Cross-linguistic influence (second language acquisition) ; Interference (second language acquisition) ; Bewegung (synt.) ; German ; English ; French