The number of European bachelor’s and master’s programmes where teaching is conducted entirely in English was 725 in 2001, 2,389 in 2007 and 8,089 in 2014. This is just 6 per cent of all university programmes in continental Europe, but we are dealing with a rapidly developing phenomenon, particularly at master’s level and in certain disciplines. And yet, other research has found resistance to change from academics.

The shift to English both in research and teaching in many European universities is essentially the side effect of the spread of international rankings. The indicators used in such rankings reward the percentage of international students enrolled. Although it has been argued that these rankings are based on a questionable methodology and that they do not properly assess the quality of research and teaching, newspapers and popular blogs relentlessly quote them.

The use of rankings therefore unfortunately entails serious problems for universities on the Continent. In some countries, the shift to English has led to legal controversies at the highest level. The Italian Constitutional Court, for example, has recently decided that the exclusive use of English in teaching violates the Italian Constitution.

In addition, teaching in English arguably decreases the quality of teaching. The Rectors’ Conference of German Universities, in a widely disseminated resolution, pointed out this risk. For example, in one study conducted on 139 Austrian undergraduates with good English skills, students attended a lecture in English given by an Italian professor using English as a foreign language at a high level of proficiency.

The content of the lesson was better understood by students when teaching was interpreted into German by a professional interpreter, as opposed to listening directly to the original in English. Most importantly, teaching given directly in German by a native teacher had greater effectiveness in communicative terms on a German-speaking audience.

In the end, what matters most in the job market are the technical skills acquired by students and these are best acquired through their mother tongue.

Finally, teaching in English is not enough to attract and retain international students. In the Netherlands, according to official data published by the Dutch Ministry of Education, only 27 per cent of international students are actually working in the Netherlands after having obtained an English degree in that country, while 70 per cent said that they wanted to stay there but eventually gave up.

One of the reasons discouraging international students from staying in Holland is their lack of skills in Dutch. Having studied two or three years only in English hinders the development of good skills in the local language and so it is harder for a country to retain their talent.

Similar results emerge from a survey conducted in Germany of 302 internationally trained students attending courses taught exclusively in English. European universities should not embrace English-only education, but rather move towards truly multilingual teaching, allowing international students to develop a repertoire including high skills in the local language.

Michele Gazzola is a member of the research group Economics and Language at the Humboldt University of Berlin and research fellow at the Institute for Ethnic Studies in Ljubljana. He is currently researching language policy, mobility and inclusion in the European Union.