title: Regex.Match double consonants in c#
body: <p>I have a list of many words. What I need is to find all words ending on "ing", "ed","ied" and with a single vowel and doubled consonant before:
  Should match words: begged, slamming, zagging. Not match helping ("lp"-not double consonant)</p>
  
  <pre><code>\w*[^aoyie][aoyie]([^aoyie])\1(ed|ing|ied)
  </code></pre>
  
  <p>It's working on RegexPal.com, but it is not working in C# (not matches any words, returns 0 words in list)</p>
  
  <p>My code:</p>
  
  <pre><code>List&lt;Book_to_Word&gt; allWords = (from f in db2.Book_to_Words.AsEnumerable() select f).ToList();
  
  List&lt;Book_to_Word&gt; wordsNOTExist = (from f in allWords
                          where Regex.IsMatch(f.WordStr, @"^(\w*[^aoyie]+[aoyie]([^aoyie])(ed|ing|ied))$")
                                      select f).ToList();
  </code></pre>
  
  <p>Works when I don't use \1. But returns words with single consonant.</p>