# File lib/cucumber/parser/natural_language.rb, line 23
      def register_adverbs(step_mother)
        adverbs = %w{given when then and but}.map{|keyword| @keywords[keyword].split('|').map{|w| w.gsub(/\s/, '')}}.flatten
        step_mother.register_adverbs(adverbs) if step_mother
      end