English is the most international language here in Europe so it should be enough to provide listing in this language. Do not use Google translate to create a listings! It usually ends up very weird or funny for everyone who knows this language and then very awkward for the owner (especially in case of EC, which is usually full of geological terms that are not handled well by google translator).
Using German and Spanish too is a good practice too, especially in these tourist destinations. The best solution would be to find somebody who speaks this language well (either local, from friends or local community in your area), who could translate you at least the EC requirements. Make sure that you have also translated the answers, so you can verify them!
If somebody really wants to know more about the subject and does not understand English, he can translate it himself using google translate to get basic idea.