Oxford Comma

The Oxford comma is the final comma in a list of items mentioned in a sentence. In this statement:

I like computer science, maths, and programming.

The comma after the word "maths" and before the conjunction "and" is considered the Oxford comma. Other commonly used terms for this style are the serial comma, series comma, or Harvard comma.

Before writing this essay, I had never added a comma to the final element of a conjunction. This topic piqued my interest, and I started researching this entity.

The term "Oxford comma" got its name from the Oxford University Press style guide. It was recommended by the Oxford style guide even when many British journals and publications did not recommend it. My first conscious encounter with it was during a diagnostic test. I was unable to correct a sentence by placing a serial comma. I had never considered a statement with a list of items wrong if it did not have a serial comma. We always try to infer the meaning from the context. But in fact, as we will see shortly, it may not always be possible. The reason to include the Oxford comma is to reduce ambiguity in a sentence.

The reason we often do not notice the lack of an Oxford comma is that the Associated Press style guide, which many newspapers follow, does not require its use. Thus, it is often left out. Let's examine an ambiguity that arises when the Oxford comma is omitted.

To my parents, Alicia and Steve Jobs.

There is ambiguity about the writer's parentage here because "Alicia and Steve Jobs" can be read as being in apposition to "my parents," leading the reader to believe that the writer claims Alicia and Steve Jobs are his parents. Placing the Oxford comma after "Alicia" resolves the ambiguity:

To my parents, Alicia, and Steve Jobs.

This sentence clearly articulates that the writer is referring to three separate entities in the dedication. However, there are cases where the inclusion of the Oxford comma can create ambiguity. For example, consider this statement:

To my father, Steve Jobs, and Alicia.

The serial comma after "my father" creates ambiguity about the writer's father because it uses punctuation identical to that used for an appositive phrase, suggesting that Steve Jobs is the writer's father. It is unclear whether there are three people (1. my father; 2. Steve Jobs; and 3. Alicia) or only two (1. Steve Jobs and 2. Alicia, with Steve Jobs being the writer's father). A common way to disambiguate this sentence is to refer to each entity explicitly. For example:

To my father, to Steve Jobs, and to Alicia.

Thus, the placement of the comma can significantly affect the meaning of an entire sentence. By appropriately choosing words and consistently using the Oxford comma, we can write less ambiguous phrases. Additionally, the Oxford comma often matches the spoken cadence of sentences better.