The Oxford Comma: Useful, Necessary[,] or Annoying?

Listing and Using (Serial) Commas

Making a list usually shouldn’t cause any trouble: You enumerate item after item, separating them with commas. The problem with the renowned Oxford comma lies in the (coordinating) conjunction at the very end of that list. Typical words between the last two items are: or, and, nor.

My son can write the letters of his name: j, a, m, e ___ s.

What Is the Oxford Comma (Serial Comma)?

Opinions are split between those who put a comma before the conjunction (the Oxford comma) and those who don't.

Other labels for this optional comma are “serial comma” or “series comma”. Most commonly, though, the comma is named after the elite university in the UK (see also Oxford spelling). Its guidelines (by the Oxford University Press) are the only ones outside of the US that strongly prefer the use of this comma. Similarly, in academic contexts, people also use the label “Harvard comma.”

05 House Style

05 House Style on the Academic Oxford University Press website

OUP Academic

After many debates and theoretic studies, there appears to be a truce now. In the US, many speakers (including the authorities of MLA, Chicago Style Guide[,] and the US Government Printing Office) use the Oxford comma. Several other publishers (e.g., Cambridge) in nations like Canada, Australia, New Zealand, South Africa[,] and the UK (except for Oxford) don’t promote it publicly.

Serial Commas and Serial Semicolons | MLA Style Center

Perhaps no mark of punctuation ruffles feathers more than the serial comma

MLA Style CenterErika Suffern

But can a simple comma really cause such confusion and almost start an international grammar war?

What Are the Arguments in Favor of the Oxford Comma?

Defenders of the Oxford comma claim that, without separating the final two items in a given list, the reader automatically combines the words.

I packed my bag and in it, I put: a book, my toothbrush, a white towel, my laptop, water and juice.

In this sentence, the list names five items. The last one is not juice on its own, but a mix of water and juice. The enumeration has no final conjunction, which is correct in casual language.

If you want to say that water is the penultimate item on the list, you should put the comma before the and, according to sticklers of the series comma. Then your list shows six items:

I packed my bag and in it, I put: a book, my toothbrush, a white towel, my laptop, water, and juice.

Another ambiguity that can be solved with the use of an Oxford comma is compound words. Some of them already include the conjunction and, like in the next example.

Besides the UK, Australia and Canada, the Commonwealth realm also consists of states like Barbados, Jamaica, Antigua and Barbuda, Saint Kitts and Nevis and Saint Vincent and the Grenadines.

The reader may conclude that Australia and Canada is another example of a unified country. Moreover, it gets hard to tell Saint Kitts, Nevis, Saint Vincent[,] and the Grenadines apart.

Besides the UK, Australia, and Canada, the Commonwealth realm also consists of states like Barbados, Jamaica, Antigua and Barbuda, Saint Kitts and Nevis , and Saint Vincent and the Grenadines.

Using the controversial comma twice, there’s no ambiguity about Australia and Canada[,] and the individual states of Saint Kitts and Nevis as well as Saint Vincent and the Grenadines.

What Are the Arguments Against the Serial Comma?

Other people claim that you can’t just disregard a grammatical rule whenever it seems to become ambiguous. If you decide to favor the Oxford comma, you need to use it every single time. Let’s have a look at another example:

Every English person has to try baked beans, French toast, fish and chips.

By not using the comma at the end of a list, the reader can understand that the sentence names three typical English dishes, fish and chips being one of them. That is where it gets complicated for defenders of the Oxford style, since you must set the comma in between the name:

Every English person has to try baked beans, French toast, fish, and chips.

Obviously, this results in a list of four items. The typical fish and chips isn’t recognizable anymore, and it’s implied that “every person should taste fish in general and chips in general”. Perhaps another and may be the solution:

Every English person has to try baked beans, French toast, and fish and chips.

As you can see, it resolves the ambiguity of the sentence (fish and chips is one dish again), but it looks wordy, it sounds weird[,] and it takes up a lot of space. Doubling the same words seems redundant.

Another counterexample even supports the idea of not using an Oxford comma twice:

Let’s introduce our dogs, Sarah and Mike.

Let’s introduce our dogs, Sarah and Mike.

Using a comma before and implies a list. The introduction is about the dogs, the person Sarah, and the person Mike, all together:

Let’s introduce our dogs, Sarah, and Mike.

Opponents of the Oxford comma claim that this ambiguity wouldn’t exist without the additional comma. Furthermore, they point out a potential apposition of the very first item in the list:

Let’s introduce our dog, Sarah, and Mike.

According to them, it remains unclear if the dog is named Sarah and the comma in doubt is only the end of the apposition. Then, it wouldn’t be a serial comma, as only two items do not make a “list.” Think of signal word, such as e.g., when it comes to listing items.

Are There Cases in Which Both Styles Fail, and How Can I Avoid Them?

There are cases that remain ambiguous—regardless of the usage of the controversial comma.

We should travel to California, San Francisco or Los Angeles.

We should travel to California, San Francisco, or Los Angeles.

Depending on your preferences, both sentences can mean three distinct things:

In order to avoid these ambiguities, you have several options:

• Using with, both, all, plus, as well, or either:

I packed my bag and in it, I put: a book, my toothbrush, a white towel, my laptop, water with / plus juice.

Let’s introduce both / all of our dogs, Sarah and Mike.

We should travel to California, either to San Francisco or to Los Angeles.

• Changing the punctuation:

Besides famous countries (UK, Australia, Canada), the Commonwealth realm also consists of states like Barbados, Jamaica, Antigua & Barbuda, Saint Kitts & Nevis and Saint Vincent & the Grenadines.

We should travel to California: San Francisco or Los Angeles.
(This also works with a period, a dash[,] or a semicolon.)

• Using a different order of the items:

Every English person has to try fish and chips, baked beans and French toast.

• Changing the sentence structure:

Sarah and Mike, let’s introduce our dogs.

Let’s introduce our dogs, who are Sarah and Mike.

• Rephrasing specific information:

Let’s introduce Mike and our dog Sarah.

The Use of the Oxford Comma Remains Controversial

In any case, try to be as unambiguous as possible—regardless of your chosen preference.

LanguageTool promotes the use of the Oxford comma. However, the writing assistant doesn’t mark the lack of it as a grammatical error; instead, it gives you a style suggestion. If you decide not to favor the serial comma, you can simply ignore those suggestions. In that case, it is just a friendly reminder of a potentially ambiguous structure which might need some clarification or rephrasing.

LanguageTool says: Have fun reading about the Oxford comma, debating it[,] and writing captivating texts!