A modified sentenceNormalizer by gregomm
 
Features:
1- Removes duplicated question marks, exclamations and periods
2- Capitalize first letter of a sentence.
3- Split sentences not only with "." but also with "?" and "!"
4- Puts a white space at the end of each sentence
5- Retains newlines
--removed from orginal function--
undestand the meaning of "¡" and "¿" in languages like spanish.
undestand the htmlentitity version of this simbols.
--removed from orginal function--
<?php
function sentenceNormalizer($sentence_split) {
 $sentence_split = preg_replace(array('/[!]+/','/[?]+/','/[.]+/'),
 array('!','?','.'),$sentence_split); 
 
 $textbad = preg_split("/(\!|\.|\?|\n)/", $sentence_split,-1,PREG_SPLIT_DELIM_CAPTURE);
 $newtext = array();
 $count = sizeof($textbad);
 
 foreach($textbad as $key => $string) {
 if (!empty($string)) {
 $text = trim($string, ' ');
 $size = strlen($text);
 
 if ($size > 1){ 
 $newtext[] = ucfirst(strtolower($text));
 }
 elseif ($size == 1) {
 $newtext[] = ($text == "\n") ? $text : $text . ' ';
 } 
 }
 }
 
 return implode($newtext);
}
?>