I am a Professor of Theoretical Philosophy at Heinrich-Heine-Universität Düsseldorf. My main research interests are in philosophy of language, in particular, implicatures and presuppositions, the debate on relativism and contextualism, indexicality and context sensitivity, and the semantic-pragmatic divide in general. I also have research interests in epistemology, especially the semantics and pragmatics of knowledge and belief ascriptions and introspection principles.