$re = '/^(?=.{2,50}$)[A-ZÆØÅa-zæøå]+(?: [A-ZÆØÅa-zæøå]+)*(?:-[A-ZÆØÅa-zæøå]+(?: [A-ZÆØÅa-zæøå]+)*)?$/m';
$str = 'Janet Smith-Johnson
Mary-Ann Johnson
Sara Mary John-Smith
Sara Johnson
Sara Mary Johnson
-Janet Mary
Mary-
- ';
preg_match_all($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