$re = '/(.*)\((Les|La|Le)\)/m';
$str = '100 mots de la Chine (Les)
Gloire de mon père (La)
Temps des secrets (Le)';
$subst = "$2 $1";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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