How to Use the Oxford Comma

How to Use the Oxford Comma

The Oxford comma is known by many names. Not sure what it is or how to use it properly? Find out below.

The Oxford comma—also known as serial comma, series comma, or Harvard comma—is the comma that is placed before the conjunction (and, but, or) when writing a list. See the examples below:

China, India and the United States are the three most populous countries.
China, India, and the United States are the three most populous countries.

The comma following India in the example is the Oxford comma, separating the second to last item from “and.” Importantly, both examples are grammatically correct. The Oxford comma is not a rule, but is dependent on style. As with all matters of style, check with your style guide and course to ensure you are following the appropriate guidelines. APA, MLA, and Chicago styles all promote the use of the Oxford comma. British English does not use this as often, and the Oxford comma is almost always left out of journalistic writing.

In most cases, the use of the Oxford comma makes your points clearer and the overall writing look more professional. For an example of ambiguity without the Oxford comma, see below.

I am inspired by artists, Einstein and Gandhi.

In this example, the sentence can be read in two different ways: either that the list has three separate items (artists, Einstein, Gandhi) or only two items (Einstein and Gandhi, both of whom are artists). In this case, the intent is to have three separate items, and using the Oxford comma would eliminate any confusion.

I am inspired by artists, Einstein, and Gandhi.

Not every list will have such ambiguity, but using the Oxford comma ensures that any such list is clear. In the example above, you could figure out the meaning (as Einstein and Gandhi were not artists), and therefore the Oxford comma is not ‘required.’ Nevertheless, it is preferred by most style guides and increases clarity. It also makes sentences appear a bit more polished.

Note: as with all matters of style, be consistent. You can choose to not use the Oxford comma, but whatever you decide, either always use the extra comma or leave it out completely. Leaving out the Oxford comma will not make your paper look unprofessional, but having it in some places and not in others will make your work seem far less professional.

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