Funny how Slovene seems to tick all the complications checkboxes :D We have 4 grammatical numbers (singular, dual, plural for 3 and 4, plural for 5 and above), they repeat at mod 100 (so 101 is singular, 102 dual,…), it's an inflectional language with 3 grammatical genders, sentence should take a different form depending on whether the user is male or female,…
http://localization-guide.readthedocs.org/en/latest/l10n/plu...