If you decide to do an international exchange programme you should be fluent in English or the speaking language of the country you are visiting. The majority of the international exchange programmes the Universities use English as a common language but there are often few exceptions.
So, before applying please check in which languages the courses you are interested in are lectured and if you need to fulfill some additional requirements.
Are you unsure if you speak a language well enough to do ERASMUS Programme?
Take unofficial test of English and test your knowledge of English language – LINK.