on Fiction University:

I recently completed an edit for a client, Cordia Pearson, whom I’d gently persuaded to let me introduce Oxford commas into her list phrases. The reasoning for this is that using the Oxford (aka serial) comma never does any harm, and can prevent serious confusion. Consider the sentence,

My parents, Jesus, and Lady Gaga taught me all I know.

If you remove the serial comma after Jesus, the meaning changes, and not for the better.

After I’d delivered the completed edit, Cordia—who was going through my every edit with admirable diligence, reading each chapter aloud as she went—emailed me to ask why I’d not introduced an Oxford comma in the last clause of the sentence,

Wish I could wail and rend my clothing as so many others do, families who have lost sons and daughters, brothers and sisters or lovers.

When I read her email, I actually remembered thinking through that sentence as I was editing, and the reason for my decision to omit the worthy Oxford comma. Stay with me as we get nerdy, friends, because this will be hugely useful in making your prose sing.