Here's a language pack that includes some of the foreign languages, like Polish and Czech. Without it you won't be able to write in those languages. https://drive.google.com/file/d/0B66ZWk4pFaQbeTdTOW9xV2JNb28/view?usp=sharing
Adding more languages
If you want o add more languages to these fonts then refer to this post:
Here's the region i've added to the spritefonts.
<!-- Latin Extended A -->
<CharacterRegion>
<Start>Ā</Start>
<End>ſ</End>
</CharacterRegion>
<!-- Latin Extended B -->
<CharacterRegion>
<Start>ƀ</Start>
<End>ɏ</End>
</CharacterRegion>