public function isQuestion($string)
    {
        $probability = 0;

        if (strpos($string, '?')) {
            $probability += 1;
        }

        $words = $this->getWords($string);

        foreach ($this->inquiryWords as $queryWord) {
            if (!strncmp(strtolower($string), $queryWord, strlen($queryWord))) {
                $probability += 1;
            } elseif (stristr(strtolower($string), $queryWord)) {
                $probability += 0.5;
            }
        }

        if ($probability >= 2) {
            return true;
        }

        return false;
    }