[patates]

Russian having singular, few (2-4), and plural (5+) forms is one from the top of my head. I can't remember any specific examples from non-cryllic ones but remember we having to duplicate a lot of translation keys to make them more context specific.

[TomaszZielinski]

Also things like:

    _('There are:') _('%d items', count=len(items))

—-which look correct until you want to translate them into a language with a different order of words in a sentence.