German requires different cases for ‘%s ago’ and ‘%s from now’

This is somewhat related to #88 , but hasn’t been resolved and also needs changes to more than the translation files I am afraid.

So what this is about is that German grammar is a beast, and prepositions require certain cases. For instance, ’vor‘ will need a dativ. ‘an hour ago’ thus translates into ‘vor einer Stunde‘, rather than ‘vor eine Stunde‘ (that’s nominativ).

humanize forms the expression ‘an hour ago‘ by piping the output of naturaldelta straight into the i18n format string for %s ago. naturaldelta() returns a nominativ, that is correct as long as the expression stands by itself. However, as soon as a preposition is placed in front of the value, the grammatical case should change.

(The same is true for ‘in ...’/‘... from now’(which currently translates into ‘... ab jetzt’ which sounds odd). Conveniently, both ‘in’ and ‘vor’ require the same case, dativ)

I would be happy to contribute, but I do not know where to start without breaking things big time. If anybody can give me some directions of how to implement this best, I would go ahead and dig my head in

I don’t properly speak any Slavic languages, but I would expect similar issues with those (correct me if I am wrong)

Start in src/humanize/time.py around the naturaldelta() output and the i18n format string for “%s ago.” Trace how the German translations for past and future expressions are assembled, then determine how the required dative forms can be represented without breaking other locales. Done means German “ago” and “from now” expressions use the correct case while existing translations remain valid.