How can I get at the matches when using preg_replace in PHP? I am trying to grab the capital letters of a couple of words and wrap them in span tags. I am using preg_replace for extract and wrapping purposes, but it's not outputting anything. preg_replace("/[A-Z]/", "<span class=\"initial\">$1</span>", $str) Solution :   Put the match in parentheses, like this: preg_replace("/([A-Z])/", "<span class=\"initial\">$1</span>", $str)