title: Regular expression to remove common whole words except those in quotes
body: <p>I've got this regular expression below which removes common whole words(<code>$commonWords</code>) from a string(<code>$input</code>) and I would like to tweak it so that</p>
  <ol>
  <li><p>it ignores those words in double or single quotes (like exact search in google search tab)</p>
  </li>
  <li><p>it remove words starting with hyphen <code>('-')</code> but not those inside double or single quotes (like negative search in google search tab)</p>
  <p><code>return preg_replace('/\b('.implode('|',$commonWords).')\b/i','',$input);</code></p>
  </li>
  </ol>
  <p>thanks</p>