title: Regex to match a word followed by another word with a certain suffix
body: <p>I need a grep regex which I want to run over a text file. The grep command should output each line of the text file which contains a word (let that word be <code>foo</code>) followed by a space and another word which ends with a certain suffix (let that suffix be <code>ing</code>).</p>
  
  <p>So the regex should match sequences such as: <code>foo going</code>, <code>foo walking</code>, <code>foo running</code></p>
  
  <p>Please not that the <code>ing</code> should be in the next word after <code>foo</code>. So the regex should <em>not</em> match: <code>foo asfd asdfing</code>.</p>
  
  <p>I tried</p>
  
  <pre><code>grep -i "foo .*ing"
  </code></pre>
  
  <p>but this matches not only on the immediate next word, it also matches if <code>ing</code> is in the second word after the <code>foo</code>. </p>