The case of the BBC

On the BBC web page you can find a lot of resources to learn languages. You can learn English, French, Spanish and German among others. There you can find grammar, games, useful phrases, tests to mesure your level and more. However, the most complete web is the one about English, in which there is also a section aimed at teachers, with innovations in English teaching and resources for the class. As you can see, the BBC provides a wide range of exercises and resources in many different languages so check it out!

Official exams

There are different official exams to test and clasify the level that a person has in a determined language. I'm going to tell you about the most important ones:
English: The Cambridge exams are recognised in many different countries fromall around the world and are required in most of European universities. There are also different types of exam depending on what you want to test, for example, business English.
The American version of the Cambridge exams is the TOEFL, which is required in the USA and also if you want to get the Australian nationality.

French: You can test your level of French by taking the DELF (Diplôme d'Études de Langue Française) exam or the DALF (Diplôme Approfondi de Langue Française).

German: You can take the Goethe Zertifikat Deutsch to test your level of German.