$re = '/\b(one|two|three|four|five|(?:s|z)ix|seven|eight|nine|zero|twelve)(?:\s|-)*/';
$str = '"one four-six nine twelve
zero eight nine nine seven three six six";';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php