At Heidelberg University, there is a one month long German Language Course offered in March about two months before the Summer Semester begins.
I would recommend this course to everyone no matter their confidence or interest level in the german language. One reason is because this is an easy way to meet and become friends with other international students both from english speaking countries and from completely different places. Also if you are interested in learning German, this course makes it possible and even really likely that you’ll make some friends who speak little to no English. A lot of my friends from this course spoke almost no english so I spoke German all the time that first month. I definitely learned the most German during this month. Another reason to take this is course is that you get to arrive early so you have time to adjust to living abroad and time to travel a bit before the semester starts and you get bogged down by classes*. And finally, I would encourage everyone to take this course at Heidelberg University because it includes a variety of free pastries, sandwiches and tea/coffee every morning, which are all unbelievably delicious (well not totally free as you have to pay for the course but even still). Also the building the course is in (Max Weber Haus) is beautiful and right across from the castle.
* At Heidelberg University you’re only allowed to miss two classes per course without a doctors note, etc. in order to receive a grade.
*** The featured image is a picture of the Max Weber Haus and the image below is a photo of one of my favorite pastries from the program that was offered the class before easter break.