I am using a translation system and for non-english plural forms, it has the concept of One, Many, Few etc.
Plural forms for non-English languages can be complex but are documented here so I could write something however is there already a C# way of knowing which plural form to use based on a number and culture?
I have looked at Enitiy Framework but this is only for English. I have also looked at Humanizer however it does not seem to have support.
You may want to have a look at messageformat and it's nuget package MessageFormat.
Messageformat is a mechanism for handling both pluralization and gender in your applications. It can also lead to much better translations, as it's designed to support all the languages included in the Unicode CLDR.
I have not used it in a while, but it looked solid.