title: How to extract words with exactly one vowel
body: <p>I have strings like these:</p>
  <pre><code>turns &lt;- c(&quot;does him good to stir him up now and again .&quot;, 
             &quot;when , when I see him he w's on the settees .&quot;,
             &quot;yes it 's been eery for a long time .&quot;,
             &quot;blissful timing , indeed it was &quot;)
  </code></pre>
  <p>What I'm trying to do is extract those words that have exactly one vowel. I do get the correct result with this:</p>
  <pre><code>library(stringr)
  str_extract_all(turns, &quot;\\b[b-df-hj-np-tv-z]*[aeiou][b-df-hj-np-tv-z]*\\b&quot;)
  [[1]]
  [1] &quot;him&quot;  &quot;to&quot;   &quot;stir&quot; &quot;him&quot;  &quot;up&quot;   &quot;now&quot;  &quot;and&quot; 
  
  [[2]]
  [1] &quot;when&quot; &quot;when&quot; &quot;i&quot;    &quot;him&quot;  &quot;he&quot;   &quot;on&quot;   &quot;the&quot; 
  
  [[3]]
  [1] &quot;yes&quot;  &quot;it&quot;   &quot;for&quot;  &quot;a&quot;    &quot;long&quot;
  
  [[4]]
  [1] &quot;it&quot;  &quot;was&quot;
  </code></pre>
  <p>However, it feels cumbersome to define a consonant class. Is there a more elegant and more concise way?</p>