Advanced C1: Ability to express yourself fluently in almost any situation, without the need to search for expressions. You are able to perform complex tasks related to work and study. You can also produce clear, detailed texts on challenging subjects.
Mastery C2: Ability to use the language with complete mastery. You have the ability to read, speak and write about any type of subject, emotion, or opinion. You are able to differentiate finer shades of meaning from the language even in more complex situations.