The Language Center of the university offers language courses of various levels which can be taken in the same timeframe as, and in addition to, your regular coursework.
To sign up for a course that has a certain prerequisite language level, you will have to take a computerised proficiency test and be matched into the right level. A certain time at the beginning of every semester during the orientation week for international students is always set aside in the Language Center expressly for taking proficiency tests and registering for German courses.
There is a nominal fee for language courses, which some guest students are able to recoup from their home universities.
Further information about which languages are offered, course schedules, and fees can be found on the Language Center website: