2020- : Vice-Spokesperson SFB 1412 at Humboldt Universität zu Berlin
2016- : Member of the Scientific Advisory Board of AcqVA
2015- : Member of the Scientific Board of the Center for Interdisciplinary Research, Bielefeld.
2013- 2020: Member of the Advisory Board of Language Science Press.
Member of the Network Language, Variation, and Migration, Universität Potsdam.
6/11-10/11: Member of the Evaluation Panel of Nordic Centers of Excellence (Norwegian Research Council).
2010- : Series Editor Brill Empirical Approaches to Linguistic Theory.
2010- : Member of Academia Net, http://www.academia-net.de/.
2006-2010: Member of the Scientific Advisory Board of NORMS (Nordic Center of Excellence in Micro-comparative syntax).
2002-2015: Spokesperson of the SFB 732 Incremental Specification in Context, University of Stuttgart
2002-2006: Member of the Center of Interdisciplinary Research, University of Bielefeld.
2000- : Series Editor at Mouton de Gruyter: Interface Explorations (with Tracy A. Hall).
1999-2009: Member of the Generative Linguistics in the Old World (GLOW) Board (positions held: Newsletter editor 1999-2002; Secretary 2002-2005, Chairperson 2005-2009).
2003-2004: Member of the Board of the Deutsche Gesellschaft für Sprachwissenshaft ‘German Linguistic Society’ (Treasurer).
2002-2003: Member of the Scientific Advisory Board of the Deutsche Gesellschaft für Sprachwissenshaft.
Consultant to the Lernaktiv project: Integration through Education, City of Stuttgart, 2005 – 2008
Member of the international advisory board to the City of Stuttgart in the area of language training, 2004 – 2009
Member of the council of the German Linguistic Society (treasurer), 2003 – 2004
Spokesperson for the Linguistic Representation and its Interpretation graduate programme (DFG Research Training Group GRK 609), University of Stuttgart, 2003 – 2006
Member of the Centre for Interdisciplinary Research, Bielefeld University, 2002 – 2006
Member of the scientific advisory board, German Linguistic Society, 2002 – 2003
Member of the Generative Linguistics in the Old World (GLOW) board, 1999 – 2009; positions held in the board: newsletter editor 1999 – 2002; secretary 2002 – 2005, chairperson 2005 – 2009
currently member of the editorial board of English Language and Linguistics, Linguistic Inquiry, Natural Language and Linguistic Theory, and Syntax.