Adding exceptions to the function
<p>I have got a function which is use to take a string and convert it to the desired form i.e. Sentence case.</p>

<pre><code>function sentence_case($string) {
$sentences = preg_split('/([.?!]+)/', $string, -1, PREG_SPLIT_NO_EMPTY|PREG_SPLIT_DELIM_CAPTURE);
$new_string = '';
foreach ($sentences as $key =&gt; $sentence) {
    $new_string .= ($key &amp; 1) == 0?
        ucfirst(strtolower(trim($sentence))) :
        $sentence.' ';
}

$new_string = clean_spaces($new_string);
$new_string = m_r_e_s($new_string);
return trim($new_string);
}
</code></pre>

<p>Now I want to modify this function for " i ", as whenever we have I in out sentence than it remain capital how can I add exception to particular words like..." i ", " i' " etc.</p>
