The German case system presents a real difficulty for students of German as a foreign language (DaF): many errors are made in student essays, which can be traced back to poor mastery of the case system. In first and second language acquisition too, case is one of the grammatical categories of the noun phrase that cause many mistakes. It is therefore not surprising that the case system is an important topic in second language acquisition and DaF research (Turgay 2011: 24f.). Supporting learners in case of problems is among the main tasks of a German teacher, but even better would be to prevent problems by raising language awareness. Hence, the question is whether case errors can be predicted so that learners have better self-control over their performance. This paper is limited to the study of case in prepositional phrases (PP) and explores the case problem in PP in Flemish learners of German, using a specially created corpus. The aim of this study is to confirm and clarify prevailing trends in the use of case in foreign language acquisition.

Keywords: second language acquisition, case acquisition, default case, prepositional phrase, determiner phrase