my locale is :de and I like to get this:
Sheet.model_name.human.pluralize # => Belegs
to add me a trailing "e" instead of "s"
Sheet.model_name.human.pluralize # => Belege
just for the Sheet-class. Can I add it somehow in my config/locales/models/de.yml ?
First of all, you need to stop using .pluralize. It uses the Inflector (which is mainly used for Rails internals, e.g. guessing table names for model Sheet -> sheets).
Sheet.model_name.human # => "Beleg"
"Beleg".pluralize # => "Belegs"
What you should do is to use the :count option.
Sheet.model_name.human(:count => 2) # => "Belege"
This requires that you have modified your de.yml as such:
de:
...
activerecord:
...
models:
sheet:
one: Beleg
other: Belege