Reviewing the Comma RulesCommas are, obviously, essential to writing. When I think of this particular mark of punctuation, I always remember a snippet of Oscar Wilde lore. According to the old quote, he spent the better part of a morning deciding whether or not to remove a comma from his poem. He finally removed it, only to reinsert said comma back into the piece that very same afternoon.

Commas can be perplexing little beasts, and they’re definitely worthy of a blog discussion. If you want your content to sparkle, you should get a consistent handle on the basic comma rules.

Commas Separate Items in a Series

This part is, hopefully, a review to most. Commas can function to separate three or more items in a series.

–I collect old teacups, colorful coffee cups, and plastic silverware.

–The best movies are True Romance, Natural Born Killers, and From Dusk Till Dawn.

I think you get the idea. Let’s not forget that commas also connect adjectives.

–The handsome, scruffy man in a suit called my name.

–Her angelic, porcelain skin reminded me of a child I knew years ago.

Commas Connect Independent Clauses

Independent clauses can stand alone as complete sentences. Effective writers know that it’s good practice to vary sentence structures by using a variety of sentence types. In order to avoid overly short, choppy prose, it’s wise to use a few compound sentences in your writing. A comma followed by a coordinating conjunction is used to connect two independent clauses.

–The couple enjoyed oysters on the half shell, and they danced on roof of the hotel.

–I never understood grammar, but I always loved to write.

Remember: If you’re going to use a comma and a coordinating conjunction, you must be connecting two independent clauses. There must be a subject, verb, and complete sentence on each side.

Error: I never understood grammar, but always loved to write.

Feedback: There is no subject in the second clause.

Correction 1: I never understood grammar but always loved to write.

Correction 2: I never understood grammar, but I always loved to write.

Subordinating Conjunctions and Commas

If a sentence begins with a subordinating conjunction, it always calls for a comma after that initial subordinating phrase or clause. If a sentence begins with an independent clause, followed by a subordinating conjunction beginning a dependent clause, a comma is only needed in rare cases of extreme contrast (see the second example below).

Although I loathe mathematics, I love counting my money.

–I love counting my money, although I loathe mathematics.

Because she loves to talk about grammar, they rarely let her speak at parties.

–They rarely let her speak at parties because she loves to talk about grammar.

Commas and Modifying ‘Not’ Phrases

Commonly used with participial phrases, commas help the reader determine exactly what a phrase is modifying. If this is all getting too technical for you, have no fear – I’ll make it super easy for you! The participial phrases are underlined once, and what is being modified by the participial phrases is underlined twice.

–Frolicking in the rainy street, she lost her red high heel.

–Pacing back and forth, the wildebeest snorted in its rusty cage.

–She watched the figure skaters twirling like spiral ribbons.

–The peeping Tom entered the yard through the back, tiptoeing through the rock garden.

Notice only one example above does not contain a comma. This is because the modifying phrase immediately follows what is being modified. There is no question about who or what is doing the twirling because it immediately follows “figure skaters.” If you’re going to add a modifying phrase to a sentence, you’re going to need a comma unless the modifying phrase immediately follows the word that is being modified.

Commas and Nonessential Phrases

If words, phrases, or clauses are not necessary to a sentence, they require commas around them. This tells the readers that the nonessential information is extra stuff.

Sentence: The sailors, lured by sirens, wrecked on the rocky coast.

Feedback: The phrase “lured by sirens” isn’t essential to understanding the sentence. It can be omitted and the meaning of the sentence doesn’t change. We still know the sailors wrecked on the coast. Because that information is not needed, it’s set apart from the rest of the sentence with a pair of commas.

Sentence: The man wearing the neon green top hat is my estranged husband.

Feedback: Only the man with the green top hat is the estranged husband, so “wearing the top hat” is essential to the meaning of the sentence.

Related tidbit: Appositive phrases rename nouns, and when they are nonessential, they are always set off my commas.

–My brother, a tattoo artist, works across the street from a major university.

–The lone holly tree, the tallest in our yard, is going to be cut down tomorrow.


An interrupter is a word (or phrase or clause) that blatantly breaks the flow of a sentence. Punctuation, typically a pair of commas, is always required before and after the interrupter. However, dashes can be used as well.

–She is, in my opinion, a boorish individual.

–It is never okay, though, to stack plates in a fine dining establishment.

–Tonight, shockingly, he cleaned up his toys and put away his clothing.

–He recently said if you must know that he refuses to pay the bill.

After Introductory Elements

Once again, this is where things can get a little tricky. I tend to use more commas in my own writing than I truly need, especially when it comes to introductory elements (and I’m a proud fan of the serial comma). English language comma rules have changed over time, and they continue to change. My brain tells me to insert a comma after an introductory element, but it isn’t always necessary anymore. We use fewer commas today; it’s a fact.

–To stay in shape, the student athletes engage in weight lifting and cardio exercises.

–In this day and age, chivalry is extinct.

–Today, people forget about comma rules.

Many people will argue against the last example, and some people may even argue against the first. I’ve heard rules that state if an introductory prepositional is less than five words, a comma isn’t needed. Like many things today (serial comma included), it’s more a matter of preference and style.

Beyond the rules, ask yourself…

Is there another form of punctuation that will work better? Sometimes a dash, period, or semicolon will work, also. If you’re unsure, sometimes it’s best to end the sentence with a period, and start that new idea in a new sentence. I always remind web writers that “less is more” on the web. While I always promote varied sentence structures, sometimes too many commas and phrases in a sentence is confusing to the reader, especially online.

Is it really necessary? When in doubt, leave it out – or at least be consistent.

While there are more comma rules, the few I mentioned today are the basics. If you’re writing your own content for your agency or business, check out the following resources for more information about the comma: The Purdue Online Writing Lab and

Or, you can always hire us to do the writing for you!

Do you have any specific questions regarding the comma rules? Or do you have your own personal pet peeve when it comes to comma errors? Comment below! We’re eager to answer your questions, and we’re always ready for a stimulating grammar discussion.