September 26th, The European Day of Languages, is a day I like to celebrate. As an aspiring polyglot, I've always felt identified with the idea of this day, even if I do not live in Europe.
Browsing the website that marks the celebration, I've found this excellent video to explain the Common European Framework for Reference -CEFR- to explain what knowledge level of a foreign language implies and entails.
What is a language knowledge level?