Add some grammar helpers to your String!

string.rb

class String
  def articleize
  	me = self.downcase
		an_startswith = ['a','e','i','o','u']
		an_exceptions = ['unit'] #add more when you think of them!

		if me.start_with?(*(an_startswith + an_exceptions))
			return "an #{self}"
		else
			return "a #{self}"
		end 
	end

	def apostrophize
		if self.downcase.end_with?('s')
			return "#{self}'"
		else
			return "#{self}'s"
		end
	end
end