My girlfriend and I live and work in Germany for 2,5 years, and are EU citizens. She works at the university, and I work as an engineer. Right now, we are preparing ourselves to take Goethe C1 language test.
The naturalization is far away, but I would to have some information on that nevertheless. According to the law we should be able to apply and get the German citizenship after living 6 years in Germany: " Bei Vorliegen besonderer Integrationsleistungen, insbesondere beim Nachweis von Sprachkenntnissen, die die Voraussetzungen des Absatzes 1 Satz 1 Nr. 6 übersteigen, kann sie auf sechs Jahre verkürzt werden. "
Goethe C1 language test (or C2 if we manage to pass it) is higher as "ausreichende Kenntnisse der deutschen Sprache" anyway, if I understand correctly?
One additional question: if persons are well integrated in German society (being member of voluntary or professional organisations, for example) is there a way to get naturalized before 6 years had passed?