My academic background is German and Germanic languages and historical linguistics. While working with the oldest Germanic language stages, my interest in variation linguistics began. Variational linguistics is the branch of linguistics that deals with language not as a single homogeneous system, but as the sum of a number of different varieties. Each variety is defined by an extralinguistic factor, such as time, place, group and type of acquisition. The 'time' factor forms the basis for dealing with different historical language stages, the 'place' factor with dialects, the 'group' factor with languages in terms of social class, religion, gender, age and subject, and the 'type of acquisition' factor with the question of the status of the language in question as a first or second language and what this means in a diachronic perspective. For the past 25 years, I have focused on Eastern European Yiddish and in particular on the varieties of Yiddish spoken by ultra-Orthodox Jewish groups, especially in the USA.

I am an experienced teacher at all levels of German synchronous and diachronic language science and language proficiency.  During my time as Head of the German Department 2007-2012, I have been in charge of all curriculum revisions for German and Dutch. In 2013, I published an article on the pedagogical value of cultural-historical digressions in theoretical language teaching. In recent years, I have supervised two talented PhD students in the 4+4 scheme and one in the 5+3 scheme.

I collaborate with representatives of German, Germanic and Yiddish linguistics, especially in Germany and the USA. From 2010 to 2021, I was a member of the board of the world's largest German studies association, the Internationale Vereinigung für Germanistik (IVG), and between 2015 and 2021 I was also its vice-president.

For many years, I have been a peer reviewer for journals, publishers and foundations in Denmark and abroad. I have also been interviewed by various radio stations about my professional work. I am currently a union representative for the Department of English and the Department of German-Romanic and a member of the Academic Council at Arts.