Grouping similar words

[kishore2k9]

hi,
how to group similar words in array
ex: kill,killing,killed,kills those words has to group them as kill only.
and the similar words which ends with removing ing,es,ed

what algorithm i have to use for my requirement to group common English words

[nrg_alpha]

I'm not sure I follow...
a) Are all these example kill, Killing, Killed, Kills all in sentences initially (like where does this array come from)?
b) and you want to remove the ing, es, ed (which simply leaves you with kill)? If so, this leaves just one word 'kill', not a group.

Sounds like a word search engine?
Although I don't quite follow, is this the general direction you are looking into?

$pattern = '#\bkill.*\b#U';
$str = 'He was simply killing time while looking for prey to kill.';
preg_match_all($pattern, $str, $matches);

foreach($matches[0] as $val){
   echo $val . '<br />';
}

ouputs:

killing
kill

But, if you absolutely need to work off of an array with mixed words (of which, some have kill in it), perhaps this is what you are looking for?

$initialArray = array('kill','killed','ant','killer','dog','killed','sun');
$killArray = array();
foreach($initialArray as $val){
   if(preg_match('#kill.*#', $val)){
      $killArray[] = $val;
         echo $val . '<br />';	
   }
}