I am not that familiar with the polish language but I know that their are complex rules for the spelling of nouns. It depends on the amount, gender and a few other things (I guess). JSON is too restrictive for that.
I glanced at the README and found the two things that I dislike in general when it comes to i18n libraries:
- JSON is not flexible enough for complex languages
(e. g. polish)
- retrieving of translation data should not be a concern of the library
@talyssonoc This criticism is not directed at _your_ library. It is a thing that bugs me in general.
My personal favourite for i18n is [newspeak] [0]. It is inspired by [Mozillas L20N project] [1].
[0]: https://npmjs.org/package/newspeak
[1]: http://l20n.org/