Joining Two Elements



  edgood  —  Grammar Tips
In a series consisting of just two elements, ordinarily you should not use a comma with the conjunction. This mistake usually occurs in a sentence with two verbs:
The committee revisited this issue and created a new rule to guide the actions of supervisors.

Not: The committee revisited this issue, and created a new rule to guide the actions of supervisors.
There is an exception to this rule. If the first of the two elements has another and within it, you might want to put a comma before the and joining the two elements, just to avoid confusion:
The committee revisited this issue and the Jones Study, and created a new rule to guide the actions of supervisors.
 

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