title: Select rows from data.frame ending with a specific character string in R
body: <p>I'm using R and I have a data.frame with nearly 2,000 entries that looks as follows:</p>
  
  <pre><code>&gt; head(PVs,15)
       LogFreq   Word PhonCV  FreqDev
  1593     140    was    CVC 5.480774
  482      139    had    CVC 5.438114
  1681     138    zou   CVVC 5.395454
  1662     137    zei    CVV 5.352794
  1619     136   werd   CVCC 5.310134
  1592     135  waren CVV-CV 5.267474
  620      134    kon    CVC 5.224814
  646      133   kwam   CCVC 5.182154
  483      132 hadden CVC-CV 5.139494
  436      131   ging    CVC 5.096834
  734      130  moest  CVVCC 5.054174
  1171     129  stond  CCVCC 5.011514
  1654     128    zag    CVC 4.968854
  1620     127 werden CVC-CV 4.926194
  1683     126 zouden CVV-CV 4.883534
  </code></pre>
  
  <p>What I want to do is to create a new data.frame that is equal to PVs, except that all entries having as a member of the "Word" column a string of character that does NOT end in either "te" or "de" removed. i.e. All words not ending in either "de" or "te" should be removed from the data.frame. </p>
  
  <p>I know how to slectively remove entries from data.frames using logical operators, but those work when you're setting numeric criteria. I think to do this I need to use regular expressions, but sadly R is the only programming language I "know", so I'm far from knowing what type of code to use here. </p>
  
  <p>I appreciate your help. 
  Thanks in advance. </p>