$re = '/([А-Яа-яЁё]+[БбВвГгДдЖжЗзКкЛлМмНнПпРрСсТтФфХхЦцШшЩщ])([ЕеИиОоЫы][Йй]|[АаИиЯя][Яя]|[ИиУуЮю][Юю]|[ЕеИиОоЫы][Ее]|[Мм][ИиУу]|[ОоЕе][Гг][Оо]|[Ии]?[АаЕеОоЫыЯя][Мм]|[АаИ и]|[ОоСсТт]{3}[Ьь]|(?<![ОоСсТт]{3})[Ьь]|[АаОо][Вв]|[АаЕеИиОо]|[Нн][АаЕеИиОо]|[Сс][Аа]|[УуЫы]|[ЕеОо][Кк]|[ИиЫы][Хх]|[АаЕеЁёИиОоУуЫыЭэЮюЯя]+)$/m';
$str = '';
preg_match_all($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