php - searching two strings for identical words -

i'm creating detecting alliteration program in php practice.

i'm starting off deleting non-alliterative words input strings valid words can considered alliteration:

//detecting alliteration  //false words $false = '\wi , @ come how in of on or when the\w';  $lines = array(      'peter piper picked peck of pickled peppers ',      'bugs bunny likes dance slow , simple shuffle ',      'you"ll never put better bit of butter on knife '      );  ($i = 0; $i < count($lines); $i++) {       } 

as might see need delete of words in false variable appear in array strings.

i've tried using preg match can't seem working. feel should pretty simple problem solve on paper i'm finding hard target individual words in strings!

any appreciated.