code: private function getCachedSingular($plural)
  	{
  		$plural = StringHelper::strtolower($plural);
  
  		return array_search($plural, $this->cache);
  	}
docs: Gets an inflected word from the cache where the plural form is supplied.
  
  @param   string  $plural  A plural form of a word.
  
  @return  string|boolean  The cached inflection or false if none found.
  
  @since   1.0