title: For the word 'operate', why OpenNLP program return type as 'NN'?
body: <p>I parsed two sentences with openNLP program</p>
  
  <ol>
  <li><blockquote>
    <p>The machines in Lab1 are unable to operate.</p>
  </blockquote></li>
  </ol>
  
  <p>It returns <em>operate</em> has type <code>NN</code></p>
  
  <ol start="2">
  <li><blockquote>
    <p>It is an uneasy time to learn java in lab1 because the machines are unable to operate</p>
  </blockquote></li>
  </ol>
  
  <p>It returns <em>operate</em> has type <code>VB</code></p>
  
  <p>Why? How can I solve it?</p>