$re = '/(?<![0-9]\.)(?<![0-9])[0-9]+(?!\.?[0-9])|\b\p{L}\b/u';
$str = '1 2 3, но не 1.1 или 14.14 & а б в a b c';
preg_match_all($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