Typology of argument structure
Morphology-syntax interface and mismatches
Research between 1990 and 2002
Project C9 'Inflectional categories and systems': Minimalist Morphology (MM)
Speaker of the SFB 282 Theorie des Lexikons
Speech Act Theory, Semantic Theory, Intonation, Word Structure, Language and Space, Questions and Answers, Several Domains of Grammar (Tense and Time Adverbials, Asymmetric Coordination, Modal Verbs, Comparative, Prefix and Particle Verbs, Participles, Structure of Prepositional Phrases)
Project 1990-95 'Lexical foundations of agreement'
Project 1988-91 'Semantics and conceptual structure of spatial localization'
Project 1985-87 'Sentence intonation and focus structure of wh-questions in German'
Project 1983-86 'Quantifiers in German' (with Löbner)
Project 1978-80 'Comparative studies of routine formulas in German and Japanese' (with Coulmas)
Project 1978-80 'Function of modalities in discourse'
Journal 1976-80 'Studium Linguistik'
Instruction books for teaching German in secondary schools 1977-90 'Thema: Sprache'