title: How to extract sentences containing specific person names using R
body: <p>I am using R to extract <strong>sentences containing specific person names</strong> from texts and here is a sample paragraph:</p>
  
  <blockquote>
    <p>Opposed as a reformer at Tübingen, he accepted a call to the University of Wittenberg by Martin Luther, recommended by his great-uncle Johann Reuchlin. Melanchthon became professor of the Greek language in Wittenberg at the age of 21. He studied the Scripture, especially of Paul, and Evangelical doctrine. He was present at the disputation of Leipzig (1519) as a spectator, but participated by his comments. Johann Eck having attacked his views, Melanchthon replied based on the authority of Scripture in his Defensio contra Johannem Eckium.</p>
  </blockquote>
  
  <p>In this short paragraph, there are several person names such as:
  <em>Johann Reuchlin</em>, <em>Melanchthon</em>, <em>Johann Eck</em>. With the help of <strong>openNLP</strong> package,  three person names <strong>Martin Luther</strong>, <strong>Paul</strong> and <strong>Melanchthon</strong> can be correctly extracted and recognized. Then I have two questions:</p>
  
  <ol>
  <li>How could I extract <strong>sentences containing these names</strong>?</li>
  <li>As the output of named entity recognizer is not so promising, if I add "[[ ]]" to each name such as [[Johann Reuchlin]], [[Melanchthon]], how could I extract <strong>sentences containing these name expressions</strong> [[A]], [[B]] ...? </li>
  </ol>