Surrounding an appositive phrase, coming before and after a nonessential clause, and placed before the conjunction in a compound sentence — these are all grammatically correct placements of commas. 

However, there is one issue regarding comma placement that is still up in the air: the Oxford comma.

The Oxford comma, also called the serial comma, is the comma that some people choose to place before the “and” or “or” and after the penultimate item in a serial list. For example, “I went to the store to buy eggs, bread, and milk,” versus “I went to the store to buy eggs, bread and milk.”

The current consensus as to whether or not the comma should be used is that it comes down to personal preference. Usage varies from person to person; some people never use it, some always do. Others toss one in here and there to their leisure, sporadically and randomly. Those people are the worst.

This disunity can cause a sense of uncertainty and unease in reading, and creates a sort of haphazard disorder between different pieces. This, to me, is frustrating — the comma should either always be there or it never should. 

So, for the sake of consistency and cohesion amongst writers, using the Oxford comma should be considered a rule, not a preference; it should be universally deemed a necessity in writing serial lists in order to prevent ambiguity. Not only can the exclusion of this essential punctuation butcher the meaning of a sentence or phrase, but it can also disrupt the flow and clarity of writing.

In the aforementioned example (eggs, bread, and milk), the discrepancy between Oxford comma usage and non-usage is fairly insignificant. With or without the comma, the same message is conveyed. But in other instances, the lack of an Oxford comma can be much more consequential.

Writing that excludes the Oxford comma can confuse readers — without a comma separating two items in a list, it’s easy to mistake them as the same item, or to misread the subsequent one as an explanation, elaboration, or definition of the first.

Take, for instance, this sentence by the Chicago Manual of Style: 

“She took a photograph of her parents, the president, and the vice president.”

Without the Oxford comma, this sentence would read, “she took a photograph of her parents, the president and the vice president.”

Here, where the sentence lacks the necessary punctuation to clearly express its meaning, the phrasing could be understood to state that the subject’s parents are the president and vice president, rather than delivering the true intent of the words, which is that the parents were in the photo with the president and vice president.

As illuminated by this example, omitting the Oxford comma can easily lead readers away from the intended idea of a sentence. Under-punctuating, in this circumstance, gives way to the potential misreading of what should be the final two items in a serial list as an appositive phrase, which renames a noun.

Perhaps the confusion between whether there were two people or four in another person’s photograph is not enough to convince opposers of this divisive comma that its presence is essential. 

However, the distinction is not always so trivial — neglecting to use the Oxford comma can produce much more detrimental repercussions. But don’t take it from me, take it from the dairy company in Maine that lost $5 million in a lawsuit involving the debated implication of a sentence that omitted the Oxford comma.

In this case, which began in 2014 and concluded in 2018, three truck drivers sued their employer, Oakhurst Dairy, for what they claimed to be four years’ worth of overtime pay that they had not received. 

According to Maine’s employment laws, companies are required to pay their workers 1.5 times their usual rate for each hour worked over 40 hours per week, with a few exceptions — meaning if the overtime hours were spent working on certain tasks, the extra payment is exempt. 

The dispute in this lawsuit was around how to correctly interpret these exceptions, which, at the time, were stated as follows: 

“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 wording of the law followed the Maine Legislative Drafting Manual, which instructs lawmakers not to use the Oxford comma when drafting Maine rules. 

The confusion was over the last part of the sentence, the bolded phrase that succeeds the comma following the word “storing”. Without an Oxford comma after “shipment”, it was unclear whether the law states that overtime pay is exempt when those extra hours are spent packing for shipment and/or distribution of the products, or whether it exempts the payment for distribution as a separate operation from packing. 

Though the law’s intent was to assert distribution as a separate exception from packing for shipment, the truckers’ lawyers were successful in arguing that as the employees had worked overtime to pack products for distribution, the company was legally obligated to pay them the overtime salary.

Though most of us probably won’t end up losing $5 million as a result of a grammar mistake at any point in our lifetimes, this case serves as an example of the uncertainty that failure to use the Oxford comma can entail. 

The best reason to consistently use the Oxford comma, as said by writer Wilson Follett in Modern American Usage, is to “preclude ambiguities and annoyances at negligible cost.”

It’s true that the comma might not always be absolutely necessary in order to deliver a sentence’s intention clearly to the reader, but it’s safe to say that the extra measure for clarity will enhance the writing in terms of comprehensibility and logical flow, while also serving as a preventative measure against the type of confusion that came about in the Oakhurst Dairy case. 

Whether in essay writing, letter writing, journalistic writing, or lawmaking (not journalistic lawmaking thanks to my use of the clarifying comma), the only socially and grammatically acceptable option should be to use the Oxford comma. 

If there were a sense of sureness that the comma will be used consistently across the board in all different formats of writing, readers would be able to carry on with ease, and writers would feel secure that their words will not be met with inconclusiveness or confusion of any sort.