What Is The Oxford Comma And When Should You Use It?

What Is An Oxford Comma

What is an Oxford comma, and what is all the fuss about?

It is called the Oxford comma because it was used by printers, readers, and editors at Oxford University Press, which is part of the University of Oxford.

In brief, what is also called the Serial Comma or Harvard Comma in American English, is a comma that is inserted before the last item in a list that is preceded by the word and, and sometimes the word or.

You shouldn’t confuse it with a normal comma, which is used with a coordinating conjunction such as but, for or so, for example.

The Oxford Comma debate

The debate about whether to use the Oxford comma or not has raged for years. But it got a lot of attention due to a court case in the US.

The state law case revolved around one clause that defined when overtime pay was to be paid to truck drivers by Oakhurst Dairy.

The canning, processing, preserving, freezing, drying, marketing, storing, packing for shipment or distribution of:

(1) Agricultural produce;
(2) Meat and fish products; and
(3) Perishable foods.

At legal issue was the last part of the introductory phrase following the last comma.

With lack of a comma before “distribution”, the clause could be interpreted to mean that the truck drivers, who had no part in “packing for shipment or distribution” should be paid because their job was “distribution” and not “packing for shipment or distribution”.

Anyway, the truck drivers won their case, and with it came the renewed interest in the use of this small piece of punctuation – the comma.

Probably because there was money suddenly attached to its use, which made it more newsworthy.

It’s only a comma. I just add one when it feels right

comma rules

No other punctuation mark causes as much trouble as the comma.

Adding a comma is not about feeling right, or when you think you would normally pause for breath or emphasis in a spoken sentence.

The use of the comma rules are quite, well, at least, reasonably clear according to the Oxford University Press Style Guide.

1. Use a pair of commas to surround a non-defining clause.

2. Do not use commas to surround a defining clause.

3. Use commas to surround a non-defining word or phrase.

4. Do not use a comma where defining information is used at the start of a sentence.

5. Do not use a comma to join two main clauses, or those linked by adverbs 
or adverbial phrases.

6. Use a comma after an introductory adverb, adverbial phrase or subordinate clause. Or use a pair of commas surrounding it if it is in the middle of a sentence.

7. Do not use a comma after a time-based adverbial phrase.

8. Use a comma between multiple qualitative adjectives (those which can be used in the comparative/superlative or modified with ‘very’, ‘quite’ etc).

9. Do not use a comma between multiple classifying adjectives: absolutes which either are or are not, such as ‘unique’, ‘English’, ‘black’ etc (although note that stylistically these can be modified).

10. Use a comma between items in a list. Note that there is no comma between the penultimate item in a list and ‘and’/‘or’, unless required to prevent ambiguity – this is sometimes referred to as the ‘Oxford comma’. However, always insert a comma in this position if it would help prevent confusion.


Comma confusion?

comma rules

In fact, this special comma is very easy to use when compared to all the other comma rules.

I can manage rule number 10 because it is not confusing at all. But I have to admit that I cheat and use Grammarly to help me with rules one to nine.

One classic example of when the comma should be used is in this famous (or perhaps infamous) book attribution.

To my parents, Ayn Rand and God.

This could easily be understood that the author’s mother is Ayn Rand and her father is God. But one comma would prevent the ambiguity.

To my parents, Ayn Rand, and God.

Generally, though, it’s very often about commas in a list.

If the last item in a list that is preceded by “and” is not to be associated with the item before “and”, the comma avoids any confusion.

So, which do you prefer? Would you like your green beans served with or without ice cream?

My menu for my dinner guests tonight will be beef stew, new potatoes, green beans and ice cream.

My menu for my dinner guests tonight will be beef stew, new potatoes, green beans, and ice cream.


My father was not at all talented at hypnosis and was a ravenous meat-eater. In the first sentence, it is clearly the opposite meaning. One small comma corrects the ambiguity in the list.

I was surprised to find myself alone with my father, a hypnotist and a vegetarian.

I was surprised to find myself alone with my father, a hypnotist, and a vegetarian.


But not everyone agrees with this Oxford style comma

oxford comma style

Let’s have a look at what some well-known English language style guides recommend when it comes to the Oxford comma. In fact, the Oxford comma is always a matter of style.

english language style guides


The Chicago Manual of Style, 16th edition (University of Chicago Press, 2010), paragraph 6.18

“When a conjunction joins the last two elements in a series of three or more, a comma … should appear before the conjunction. Chicago strongly recommends this widely practiced (sic) usage.”

The Times style manual

“Avoid the so-called Oxford comma; say ‘he ate bread, butter and jam’ rather than ‘he ate bread, butter, and jam’.”

The New York Times stylebook

“In general, do not use a comma before and or or in a series.”

The Australian Government Publishing Service‘s Style Manual for Authors, Editors and Printers

“A comma is used before andor, or etc. in a list when its omission might either give rise to ambiguity or cause the last word or phrase to be construed with a preposition in the preceding phrase. … Generally, however, a comma is not used before andor or etc. in a list.”


BuzzFeed uses the serial (aka Oxford) comma: e.g., We picked up cyan, magenta, yellow, and black balloons for the party.

Cambridge University Style Guide

An Oxford comma is the final comma used before an “and” at the end of a list and is used to avoid ambiguity:

The family meal was soup, fish and chips, and ice cream.

The jumper is available in green, yellow, and black and white.

Associated Press Style Guide (AP Style)

The Serial Comma/Oxford Commas

The serial comma is a comma that appears before “and” in a list. Omit the serial comma unless the sentence would be unclear without it.


I think that makes four guides that are for the comma and three against it. So it is a close vote.


Which comma rule should you use?

Due to the different stances that are taken by the style guides above, it is clearly up to you to decide.

But it is more about style than strict grammar rules.

However, when you are not sure, or if you think your readers will be in doubt, use the extra comma.

You don’t have to be a slave to it but rather look at its use as being a tool to improve the clarity of your writing.

And yes, I am definitely an Oxford comma proponent. Are you?

Derek Haines

A Cambridge CELTA English teacher and author with a passion for writing and all forms of publishing. My days are spent teaching English and writing, as well as testing and taming new technology.

5 thoughts on “What Is The Oxford Comma And When Should You Use It?

  • July 6, 2018 at 2:42 am

    I use it only to avoid confusion.

  • July 5, 2018 at 10:03 pm

    I advocate using the Oxford comma as a complete rule. This avoids the ‘eats shoots and leaves’ error. Also, it enables the absence of the comma to be an indication that the words where it doesn’t appear are grouped. Without it, what seems perfectly clear to you may still confuse another person.
    ‘We bought fruit drinks, and bananas, and fish and chips, and peaches and cream, cakes, and scones’ (Or ‘peaches, and cream cakes’.)
    We bought fruit, drinks, and bananas, and fish, and chips, and peaches, and cream, cakes, and scones
    We bought fruit drinks and bananas and fish and chips and peaches and cream cakes and scones

  • July 5, 2018 at 1:10 pm

    Very enlightening. Thank you.
    Question for you: why didn’t you use “my” before dog? Just curious.

    • July 5, 2018 at 1:33 pm

      Hi Cynthia.

      I could have used “my” again before “dog” and without a comma.

      In a simple list, you would only use “my” once. “I like my house, car and computer.

      But in a list where it is more complex, or unclear, the comma helps avoid the repetition of “my”.

  • June 16, 2018 at 12:50 pm

    I’m a ‘use it if the sentence would otherwise be confusing’ person, but if it is perfectly clear without it, I omit it.


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