If there was an award for the most controversial comma (and, yes, what an exciting award that would be), it would undoubtedly go to the highly disputed Oxford comma.
This unsuspecting comma is the subject of much heated debate amongst grammarists, and this doesn’t help matters for ESL students.
What is the Oxford Comma?
The Oxford comma is also known as the serial comma, series comma or Harvard comma. These names are interchangeable, and you may be more familiar with one or other of them based on what part of the world you live in.
Quite simply, the Oxford comma is the comma that comes before the and or or connecting the last item in a list of things in a sentence.
For example:
The experiment recorded the patient’s temperature, blood pressure, and pulse.
The study site was windy, cold, and isolated.
There must be at least three things in the list for the Oxford comma to be used.
Should I use the Oxford Comma?
Most of the time it’s up to you whether you use the Oxford comma. If you’re following a style guide, it will tell you what to do.
If you’re not following a style guide, make a decision and stick to it: make sure your usage (or non-usage) of the Oxford comma is consistent throughout your document.
When should I use the Oxford Comma?
Sometimes, the Oxford comma is needed to reduce ambiguity.
Consider this sentence:
The subjects covered in this course are forensics, physical and organic chemistry and chemical formulations.
How many subjects will the course cover? Are physical and organic chemistry two different subjects or parts of the same subject? Are organic chemistry and chemical formulations parts of the same subject?
Without the Oxford comma, we can’t answer these questions.
What happens when we add the Oxford comma to this sentence?
The subjects covered in this course are forensics, physical and organic chemistry, and chemical formulations.
Now we know that the course covers three subjects which are:
- forensics,
- physical and organic chemistry, and
- chemical formulations.
Another example of using the Oxford comma to reduce ambiguity is related to the famous (and probably fictional) book dedication:
To my parents, Ayn Rand and God.
The above sentence has no Oxford comma and we are left wondering… are the author’s parents Ayn Rand and God??
Simply adding in an Oxford comma provides some much-needed clarity here:
To my parents, Ayn Rand, and God.
Take-home Message
Unless you’re an English scholar or grammarist, don’t get bogged down with the details of the Oxford comma.
All you need to do is remember the following three things:
- If you are following a style guide, do what it tells you.
- If the Oxford comma reduces ambiguity: use it.
- If you are not following a style guide and the sentence is not ambiguous, you can decide whether to use the Oxford comma. The most important thing is to be consistent.