private function hasValidSEnding($word)
    {
        $lastLetter = Utf8::substr($word, -1, 1);
        if (in_array($lastLetter, array('b', 'c', 'd', 'f', 'g', 'h', 'j', 'l', 'm', 'n', 'o', 'p', 'r', 't', 'v', 'y', 'z'))) {
            return true;
        }
        if ($lastLetter == 'k') {
            $beforeLetter = Utf8::substr($word, -2, 1);
            if (!in_array($beforeLetter, self::$vowels)) {
                return true;
            }
        }
        return false;
    }