protected function rv()
    {
        $length = Utf8::strlen($this->word);

        $this->rv = '';
        $this->rvIndex = $length;

        for ($i=0; $i<$length; $i++) {
            $letter = Utf8::substr($this->word, $i, 1);
            if (in_array($letter, self::$vowels)) {
                $this->rv = Utf8::substr($this->word, ($i+1));
                $this->rvIndex = $i + 1;
                return true;
            }
        }

        return false;
    }