Reverse each word of a string separately :

Example : Hello World = olleH dlroW

<?php

$string = "How are you";
$strRev = explode(" ", $string); //Array ( [0] => How [1] => are [2] => you )

//Now take every single string using foreach function.
foreach($strRev as $str_rev){
    echo strrev($str_rev). ' '; // OP = woH era uoy
}

?>