Hi,
please consider adding the following rule:
<rule id="ID" name="common typo">
<pattern>
<token>a</token>
<token>but</token>
</pattern>
<message>a bit instead of a but</message>
<example type='incorrect'>So I confused things <marker>a but</marker> and it was Kai Ahrens who had planned that.</example>
<example type='correct'>So I confused things a bit and it was Kai Ahrens who had planned that.</example>
</rule>
Thanks,
Jan