The Assistant professor of Indology,University tubingen, Germany.

1978-1980 Associate Professor of Sanskrit,Instituut Kern, University of Leiden,The Netherlands

1981-1986 Professor of Sanskrit language and literature University of Leiden,The Netherlands

1986-1987 Visiting Professor of Sanskrit,Harvard University

1987-Harvard University,Wales Professor of Sanskrit,Faculty of Arts and Sciences,Harvard University

1997 Invitation to become Prof of Indology and head of the Department Indology and Iranin Studies,Munich University,Germany,declined,as to remain at Harvard.

1999-President, Association for the Study of Language in Prehistory, Boston