When do you put a comma before “and” or “or”?

The Oxford comma is when you put a comma before “and” or “or” or another conjunction, at the end of a list of three or more items.

e.g. I like to read books, write books, and talk about books.

e.g. I like to read, write, but not talk about books.

The Oxford comma is a special comma guidelines used by a lot of style guides here in Australia, including the style guides at QSuper and Canstar, which I wrote during my time there.

Why use the Oxford comma?

There are three reasons to use the Oxford comma:

  1. Makes a sentence clearer if there are multiple “and”s.
  2. Without the comma, the end of the sentence can become the observer/receiver of the sentence (incorrectly).
  3. Without the comma, the end of the sentence can become a descriptive clause (incorrectly).
Image source: SayingImages.com

Using commas to make sentences easier to read

First, the Oxford comma is helpful because it separates the last item in the list from the second-last item, making the sentence clearer.

Here’s a comparison of using the Oxford comma vs not using it:

e.g. With the comma: QSuper now offers multiple different types of insurance, including death, total and permanent disability, and income protection cover.

e.g. Without the comma – less clear: QSuper now offers multiple different types of insurance, including death, total and permanent disability and income protection cover.

Using commas to keep sentences correct

Secondly, the Oxford comma is helpful because without the last comma, it can seem as if the end two items of the list are the observer or receiver of your sentence. An example can explain this better than I can:

e.g. With the comma: I love my pets, family, and friends.

e.g. Without the comma: I love my pets, family and friends. >>> You are actually telling your family and friends that you love your pets, i.e. “Family and friends, I love my pets.”

Thirdly, the Oxford comma is helpful because without it, it can seem as if the end two items of a list are describing the rest of the sentence (“a descriptive clause”, if you want to get nerdy).

e.g. With the comma: I love my pets, Mum, and Dad.

e.g. Without the comma: I love my pets, Mum and Dad. >>> I am saying that Mum and Dad are my pets, and they would really not be happy about that.

Why is it called the Oxford comma?

Now let’s get really nerdy! The “Oxford” comma is called by this name because it was traditionally used by the Oxford University Press editors and printers.

They also called it the “serial comma” because it’s used for lists, but since “serial” makes me think of serial killers, I don’t use that name.

Now, the Oxford Style Guide themselves dropped the “requirement” for an Oxford comma in all cases in 2011, and made it a guideline instead.

But there are still got many good reasons to use the Oxford comma, so I’m happy it’s sticking around.

As far as I’m concerned, there are three scenarios: using the Oxford comma correctly, not using the Oxford comma and being wrong.

(Joke. But seriously, it physically hurt me not to put the comma there.)

(C) TJ Withers-Ryan, 2022. Please credit me when you repost or share. Thanks!

2 thoughts on “When do you put a comma before “and” or “or”?

  1. Oxford commas for life. Unless, of course, a publisher says not to use it in the manuscripts I send in. Or if a certain place of employment doesn’t use them as house style. But yeah, Oxford commas forever.

    Liked by 1 person

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