$re = '/(\s+)?(.+?)(\s+)?(years?|months?).*/m';
$str = ' Eight years blah blah 50 blah blah, two years blah blah blah.
Eight years blah blah 50 blah blah, two years blah blah blah.
Eight months blah blah 50 blah blah, two years blah blah blah.
One month blah blah 50 blah blah, two years blah blah blah.';
preg_match_all($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