private function step0()
    {
        $this->word = preg_replace('#([q])u#u', '$1U', $this->word);
        $this->word = preg_replace('#(['.$this->plainVowels.'])y#u', '$1Y', $this->word);
        $this->word = preg_replace('#y(['.$this->plainVowels.'])#u', 'Y$1', $this->word);
        $this->word = preg_replace('#(['.$this->plainVowels.'])u(['.$this->plainVowels.'])#u', '$1U$2', $this->word);
        $this->word = preg_replace('#(['.$this->plainVowels.'])i(['.$this->plainVowels.'])#u', '$1I$2', $this->word);
    }