As a writing professor, I receive a lot of free grammar handbooks. Most of these, enumerate the rules of comma usage to a degree that even I find daunting. Most list at least eight rules. Several list over ten. One contains twenty-four rules for proper comma usage.
Today, I will set the record straight for the weary student. In my opinion, one needs only three rules to rule [almost] all commas.
Rule One: Lists
It is no secret that commas separate items in a list.
I eat raw oysters, blanched squid, and seared salmon.
The only challenge comes from that final comma, known to experts as the Oxford comma and made famous by Vampire Weekend’s song by that name. The song begins, “who gives a fuck about the Oxford comma?” The answer is: I do. And although it is not required, I believe that omitting the Oxford comma shows a lack of sophistication and possibly a tendency toward slovenliness.
Rule Two: Extra Stuff
If your sentence contains phrases that could be removed without altering the essential meaning of the sentence or damaging its grammatical structure, those phrases should be offset by commas.
Although arguably a sociopath, my brother is a very likable fellow.
My brother, despite being a sociopath, is a very likable fellow.
The controversy here comes from the essence of “essential meaning.” When we English professors argue about comma usage, it is usually in cases such as these where one might deem a phrase auxiliary in one sentence and essential in another. If challenged on commas such as these, simply sigh and say, “It’s stylistic.”
Rule Three: Before a Conjunction Before an Independent Clause
Finally, we arrive at a point where some understanding of grammatical vocabulary is necessary.
A conjunction is one of these words: for, and, nor, but, or, yet, so, remembered often by the acronym FANBOYS. Remember the Conjunction Junction?
An independent clause could stand alone as its own sentence.
Independent: I am a shark.
Dependent: Because I am a shark.
Independent: I chase you down.
Dependent: Viciously chasing you down.
Put these pieces of information together and you have the rule. A comma precedes a conjunction that introduces an independent clause.
I believe I am a squid, and this causes many problems for me at cocktail parties.
I believe I am a squid and thus have many problems at cocktail parties.
Are there other comma usage rules? Yes. Does 95% of the English speaking population need to know them? Probably not. Learn these three and proceed with confidence.
Karelia is a professor by day, novelist by night.