$re = '/(?:(?:[uo7])+[\s]*[wn]+[\s]*(?:[uo7])+)+/mi';
$str = 'owo
uwu
oooowwwoooo
uuuuuwwwuuuu
UUUUUUUUWWWWWWWUUUUUU
OOOOO WWWWW OOOOOOOOO
7w7
7 w7
7 w 7
unu
u n u
7n7
7 n 7';
preg_match_all($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