public function isSingular($word)
	{
		// Try the cache for a known inflection.
		$inflection = $this->getCachedPlural($word);

		if ($inflection !== false)
		{
			return true;
		}

		$pluralWord = $this->toPlural($word);

		if ($pluralWord === false)
		{
			return false;
		}

		// Compute the inflection to cache the values, and compare.
		return $this->toSingular($pluralWord) == $word;
	}