Was bedeutet "Leistungsniveau"?

Anyone, whether a beginner or an advanced learner, can attend a German course at a German school and spend time with participants who speak German as well or as poorly as he or she does. This means that in a German course there are usually only people with a certain level of knowledge, so that no one speaks German much better than anyone else. This is the only way to ensure that no one is overwhelmed or underchallenged, but can learn as much as possible and as quickly as possible. Such a homogeneous group can only be created if all participants are assigned to groups. And this is exactly what is done with the performance levels. All those who do not speak any German at all are accepted at a German school in courses at level A0, those with very little knowledge at level A1 and so on. The range goes up to C2, which is almost native speaker level and is only offered by a few German language schools.