Would you like to know your level of English for your work, be able to appreciate your mastery of German or know where you are in Spanish without taking a language test? Use this evaluation grid of the Common European Framework of Reference for Languages created by the European Union. Read the instructions for each level and find out where you stand! The Common European Framework of Reference for Languages has established 3 levels of proficiency in a foreign language (A, B and C), each of which is divided into two levels (1 and 2).
Thus, A1 is the lowest level and C2 is the highest level. AO mentioned sometimes is not a level, but simply a way to clarify that you do not possess any knowledge in the target language.