morphos\RussianGeneralDeclension::getPrefixOfFirstDeclension PHP Метод

    protected function getPrefixOfFirstDeclension($word, $last)
    {
        if (in_array($last, ['о', 'е', 'ё', 'ь', 'й'])) {
            $prefix = slice($word, 0, -1);
        } else {
            $prefix = $word;
        }
        return $prefix;
    }