Re: two language website
Yes. As long as there is an easily-accessible human translation of the site's content in English, French or Spanish, you can use whatever other language you want. The "supported languages" do not have to be the primary/default language for visitors to the site; your primary interface can be in German as long as it's obvious how to get to the English version. And because the requirement is for a human translation (mostly because machine translations can vary between absolute gibberish at worst and occasionally misleading at best) it's understood that there will be some lag between the time that user-generated content (questions and comments) are posted and the time that a proper translation becomes available -- just don't leave it too long.
“Beware of bugs in the above code; I have only proved it correct, not tried it.” --Donald Knuth
"It was as if its architects were given a perfectly good hammer and gleefully replied, 'neat! With this hammer, we can build a tool that can pound in nails.'" -- Alex Papadimoulis (on TheDailyWTF.com)