The Oxford comma: When and how you should use it

What is an Oxford comma, exactly?

Also known as the serial comma, the Oxford comma is a comma placed before the conjunction at the end of a list. It is commonly referred to as the Oxford comma because Oxford University Press has long been known for its style of retaining or imposing the comma consistently. For example:

• I had yogurt, toast, and fruit for breakfast.

Some style guides (including The Guardian and Observer style guide and The Associated Press Stylebook, to name two) opt for a simplified use. So, in the case of the simple list above, the serial comma would not be necessary. Without the comma, it reads:

• I had yogurt, toast and fruit for breakfast.

No one assumes that the toast and fruit are a single item – it’s understood that these are two separate entities within a list and spare the text extra punctuation, making for a streamlined reading experience. That said, they do agree that a serial comma should be used in a series if the meaning is otherwise unclear, for instance:

• I would like to thank my parents, Angela Merkel and Elton John.

Here, a comma would help to avoid the implication that my parents are Angela Merkel and Elton John:

• I would like to thank my parents, Angela Merkel, and Elton John.

The AP Stylebook further clarifies its guidance by specifying that a serial comma should be used:

1. Before the concluding conjunction in a series if an integral element of the series requires a conjunction

• My favourite pub lunch is a seitan steak and ale pie, roast potatoes, and brussels sprouts.

2. Before the concluding conjunction in a complex series of phrases

It is vital to check what temperatures are expected in the place you are visiting, what kind of activities you will engage in upon arrival, and if you are expected to attend any formal events or events with a strict dress code.

Rules are great! What else is there to discuss?

As much as I love rules, it’s always good to think critically about them. This piece on Medium argues against using the serial comma at all, its main point being that writing should be clear and understandable. In many cases, lists of the sort above that necessitate a serial comma come across as ambiguous or difficult to read. This ambiguity can be solved by rewriting. For instance, the first example could instead read:

• I would like to thank Angela Merkel, Elton John and my parents.

This phrasing immediately clears up any unwanted implications about parents and famous people.

For the second example:

• My favourite pub lunch is a seitan steak and ale pie with roast potatoes and brussels sprouts.

Here, I’ve separated the main from the sides to make the sentence more readable without excess punctuation.

The third example is a difficult one because it has a lot of separate clauses. Even the Hemingway Editor – a great tool to use when writing in English – says my sentence is very hard to read. Here’s how I could break it down:

• It is vital to check what temperatures are expected in the place you are visiting. Please also consider what kind of activities you will engage in upon arrival. Lastly, ask whether you are expected to attend any formal events or events with a strict dress code.

Why all the fuss? With all these exceptions and changes, wouldn’t it just be easier to use the Oxford comma consistently?

It’s true that this method may come across as inconsistent, which is why it seems a lot of people make the all-or-nothing argument either in favour or against. Unless it’s consistently done correctly in the body of work, you could end up with a mess of commas and seemingly missing commas. If your writing involves a lot of complex series, the rule of majority might come into play – you’ve got a lot of clarifying commas in there so it would feel inconsistent not to use a serial comma. Especially in legal writing, you may not be able to avoid complex series.

A few years ago, the lack of a serial comma resulted in a five-million-dollar payout to drivers of Oakhurst Dairy for unpaid overtime because of an ambiguous sentence. At the time, under Maine state law, workers were not entitled to overtime pay for the following activities: “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.” The key here is the “packing for shipment or distribution of”, which in this case comes across as a single activity. Because truck drivers don’t pack food but do in fact ship and distribute it, the exemptions for overtime didn’t apply to them. The law has since been changed, but the victory punctuates the importance of clear writing and a well-placed comma.

When asking yourself if you should use a serial comma, consider: could your sentence be easily misunderstood? If yes, you could use that serial comma, or you can take a note from our suggestions above to rewrite your sentence more clearly. Ultimately, our advice is to choose your style and stick to it.

At EnglishBusiness, we understand the importance of good style and a clear corporate voice. We’d be happy to help you decide what’s right for you and develop your voice. Get in touch with us to see how we can help.