English: Could've having + have having + what's

Here a rule for “'ve having”

<rule id="VE-HAVING" name="ve Having">    
         <pattern>
          <token regexp='yes'>could|would|should|you|i|we|they</token>
          <marker>
            <token spacebefore="no" regexp="yes">['`]</token>
            <token>ve</token>
            <token>having</token>
          </marker>
         </pattern>
         <message>Did you mean <suggestion><match no="2"/><match no="3"/> been having</suggestion>?</message>
         <example type="incorrect" correction="'ve been having">I<marker>'ve having</marker> lunch.</example>
         <example type="correct">I've been having lunch.</example>
        </rule>

And “Have-having”

<rule id="HAVE-HAVING" name="Have Having">    
         <pattern>
          <token >have</token>
          <token>having</token>
         </pattern>
         <message>Did you mean <suggestion><match no="1"/> been having</suggestion>?</message>
         <example type="incorrect">I <marker>have having</marker> lunch.</example>
         <example type="correct">I <marker>have been having</marker> lunch.</example>
        </rule>

Also, I’ve spotted that the “what’s” case is missing from the ITS_IS, so a possible update could be…

<rule id="ITS_IS" name="its is (it is)">    
  <pattern>
    <token regexp="yes">what|it|who|she|he|there|that</token>
    <token regexp="yes" spacebefore="no">['’]</token>
    <token>s</token>
    <token>is</token>
  </pattern>
  <message>Did you mean <suggestion><match no="1"/> is</suggestion>?</message>
  <example correction="She is"><marker>She's is</marker> the best dancer on the west coast.</example>
  <example>She's the best dancer on the west coast.</example>
  <example type="incorrect" correction="What is"><marker>What's is</marker> achievable in the given time frame.</example>
  <example type="correct">What is achievable in the given time frame.</example>
</rule>

Thanks, I’ve added those rules and the correction. The changes should become live on languagetool.org tonight.