My current Application has a complete english translation, but i can't make sure additional languages are fully implemented, too.
This results into translation_missing warnings or rather strings like "de, install, steps, language"
Is there a way to tell rails to use the english translation in case there is no (in this example) german one?
perhaps you could use this with some slight modifications: http://github.com/javan/rails-i18n-translation-inheritance-helper
@tsdbrown's is a good suggestion. Mine is a bit more simplistic. When you create your German resource file, for instance, one way to approach it is to start with your English file, and pass the that to your translators. Whatever they don't translate still exists, just in English. Then you don't have this problem at all. One more advantage to using this method is that you ensure when you want to translate the file completely, you don't have to do a giant search and compare to add the missing strings.