I just answered this question on Quora. As the answer is quite lengthy and could be interesting for someone else, here it is:
Hi! I moved to Vienna one year ago and I went to a polytechnic school for one year. I heard that you can’t get into a gymnasium without an advanced German knowledge. My nivel is somewhere between A2-B1. Can I go to a regular high school?
I don’t know your age, that could be relevant to this question as well, but I will answer as good as I can.
I don’t think that you have to prove a particular level of German before you can start Gymnasium if you have fulfilled all other requirements, but honestly, I would not suggest it before learning better German. The classes will be held in German and the level is C2. You will not understand most of the classes and the exams are all in German.
Also in order to finish Gymnasium you will have to do the Matura and that includes writing a big essay in German in C2 level.
But there are many options you can take:
Spend a year or so and learn German and then go to a Gymnasium could be a good option. I would take a course that seems to help you and also spend as much time practicing, talking to people, reading books (there are good options for “Graded Readers”, using the dictionary a lot.
Start with Gymnasium, but be prepared to repeat the first level and mainly concentrate on learning German. It could work, you will be surrounded by people who speak German, hopefully make German-speaking friends, etc.
In any of those cases – you might have to do a “Hauptschulabschluss” if you don’t have it already (you probably have when you did the polytechnic school). Either the certificates of your country are valid and you get credited or you might have to do an exam showing that you basically learned what you need to learn in the first 8 years of school.
If you are planning to go to University and therefore want to go to Gymnasium you could consider another option:
Try finding a “Lehre” (again, don’t know how old you are) – that is vocational training for 3 years. You will also have a language barrier, but if you are good otherwise and willing to learn and work well and particularly learn German fast, it is a good possibility. Many companies are looking for trainees desperately.
You can do it for many professions from Computer programing to learning to be an Electrician. It is training on the job plus one day of school a week and you get paid for it. Concurrently or after that you can do a “Berufsmatura” (Professional Matura I would call it), which has in Austria (not in all other countries though) the same value as a normal Matura, but it only consists of 4 exams. When you do it concurrently to your Lehre also the preparatory courses are free. The exams are English, German, Maths and one subject relating to your “Lehre” (Apprentice Program). Also that way you get professional experience which can be of value later, both for university and applying for a job. There are also companies that support their trainees to do the Berufsmatura.
In any case – work on learning German fast! Don’t be discouraged, it can be a bit tricky. Here are a few tipps that might help:
Don’t worry about grammar so much in the beginning. Nobody can learn a foreign language and be perfect and fluent right from the start. Anybody who expects this is setting up the student for losses.
If you cannot understand what your teacher is trying to explain, find someone who can – either a different class or maybe even youtube can help, there are many channels for German learners.
Work on getting a good vocabulary in the beginning. When you learn new words, do learn which gender (der die das), even if you are not 100% sure how to use it. Repeating the word and its translation and making sentences with it helps (even if the sentences are not perfect or even mixed with your own language).
Watch Netflix or Prime in German with English subtitles. Try documentaries or cartoons first – if they speak a bit slower. Perfect would be programs that are originally German and provide subtitles in your language, but this is probably not available. You can use however a documentary series for example, put the language in German and English subtitles.
Find books that are made for German learners. There are a lot of offers on Kindle. “Scribd” is paid but has a lot of texts. Also public libraries in Vienna will have those (the most you find in the main library close to the Westbahnhof).
Talk German as much as you can.
Never be shy to ask what something means and do it every time you don’t understand something if you can!
If you decide to go to a Gymnasium and you are 17 or above a good option could be the “Abendgymnasium für Berufstätige” in Vienna. (They have them in other cities as well).
First of all, they are open to people with very different backgrounds. Also the school is organized in another way than usual schools and can be combined very well with having a job. You can learn better in your own pace and take on more or less classes, depending on how much you can manage. You will never have to repeat all of the classes for an entire school year if you flunk one subject, only that subject.
Here is the link to the article in Quora: