$re = '/((\(([а-яё]\|?)+\)|[CV^$])*) ([а-ё]) ((\(([а-яё]\|?)+\)|[CV^$])*)/x';
$str = '(ш|ж|ч|ц|щ)и(й)
а
(ь|ъ)е
ш(ь)V
Vй$
Vё
ж(ь)V';
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