title: How to add tags to negated words in strings that follow "not", "no" and "never"
body: <p>How do I add the tag <code>NEG_</code> to all words that follow <code>not</code>, <code>no</code> and <code>never</code> until the next punctuation mark in a string(used for sentiment analysis)? I assume that regular expressions could be used, but I'm not sure how.</p>
  
  <p><strong>Input:</strong><br><code>It was never going to work, he thought. He did not play so well, so he had to practice some more.</code></p>
  
  <p><strong>Desired output:</strong><br><code>It was never NEG_going NEG_to NEG_work, he thought. He did not NEG_play NEG_so NEG_well, so he had to practice some more.</code></p>
  
  <p>Any idea how to solve this?</p>