The "zentrum für deutsche sprache und kultur e.V." is part of the global TANDEM net.
TANDEM® International is a member of WYSETC (World Youth Student & Educational Travel Confederation) and ALTO (Association of Language Travel Organisations).
More Informations on the TANDEM Foundation you'll find at:
TANDEM language Exchange
Tandem is a special method of actively learning languages. Tandem means working together. You'll meet a local person who is learning your language, both of you meet regularly, speak alternately in the foreign language and your language. You should have basic language knowledge.