module ActiveModel::Translation

def human_attribute_name(attribute, options = {})

Specify +options+ with additional translating options.

Person.human_attribute_name("first_name") # => "First name"

instead of "first_name".
Transforms attribute names into a more human format, such as "First name" 
def human_attribute_name(attribute, options = {})
  options   = { count: 1 }.merge!(options)
  parts     = attribute.to_s.split(".")
  attribute = parts.pop
  namespace = parts.join("/") unless parts.empty?
  attributes_scope = "#{i18n_scope}.attributes"
  if namespace
    defaults = lookup_ancestors.map do |klass|
      :"#{attributes_scope}.#{klass.model_name.i18n_key}/#{namespace}.#{attribute}"
    end
    defaults << :"#{attributes_scope}.#{namespace}.#{attribute}"
  else
    defaults = lookup_ancestors.map do |klass|
      :"#{attributes_scope}.#{klass.model_name.i18n_key}.#{attribute}"
    end
  end
  defaults << :"attributes.#{attribute}"
  defaults << options.delete(:default) if options[:default]
  defaults << attribute.humanize
  options[:default] = defaults
  I18n.translate(defaults.shift, options)
end

def i18n_scope

Returns the +i18n_scope+ for the class. Overwrite if you want custom lookup. 
def i18n_scope
  :activemodel
end

def lookup_ancestors

ActiveModel::Translation#human_attribute_name.
ActiveModel::Errors#full_messages and
method, which is used in ActiveModel::Name#human,
When localizing a string, it goes through the lookup returned by this 
def lookup_ancestors
  ancestors.select { |x| x.respond_to?(:model_name) }
end