You’ve mastered basic grammar, know your “its” from your “it’s,” and you’re pretty confident with punctuation—so why do some of your sentences still feel off?
There’s a good chance the culprit is a sneaky little mistake that flies under the radar for even seasoned writers: the comma splice.
It looks innocent. It even sounds okay when you read it out loud. But this one mistake can make your writing feel rushed, unpolished, or amateurish—and readers will notice.
In this article, we’ll break down what a comma splice actually is, why it matters, and how to fix it with simple, powerful tools. You’ll walk away with stronger sentences and a sharper editorial eye.
What Is a Comma Splice (and Why Is It a Problem?)
A comma splice happens when two complete sentences (also called independent clauses) are joined with only a comma—and no conjunction, semicolon, or proper punctuation to hold them together.
Example of a comma splice:
The sun was setting, we hurried home.
Both parts—The sun was setting and we hurried home—could stand alone as full sentences. But the comma isn’t strong enough to glue them together.
Why it’s a problem:
Comma splices create run-on sentences that feel rushed, unpolished, or even confusing. They make the pacing choppy and the tone less professional—even if the writing otherwise seems fine. Readers may not know the grammar rule, but they’ll feel that something’s off.
This error is easy to miss because the sentence sounds okay, especially when read aloud. But grammatically, it's a structural crack in your writing.
Common Examples You Might Not Realize Are Wrong
Comma splices often slip into writing because they sound natural—especially in casual speech or fast-paced narration. That’s what makes them so dangerous: they feel right even when they’re grammatically wrong.
Here are some examples that might look familiar:
- She loves thrillers, she reads one every week.
- I wanted to go to the party, I had already made plans.
- He’s a great writer, his grammar needs work.
- The rain poured down, we kept walking anyway.
At first glance, these sentences seem fine. But each one connects two complete thoughts with nothing but a comma.
Why it matters:
Even if readers don’t consciously spot the error, these sentences can feel rushed or oddly structured. And in longer passages, repeated comma splices can seriously disrupt the flow of your prose.
The good news? Once you learn to spot them, they’re incredibly easy to fix.
How to Fix a Comma Splice
Fixing a comma splice is easier than you might think! One key tool is the coordinating conjunction, often remembered by the acronym FANBOYS:
- For
- And
- Nor
- But
- Or
- Yet
- So
These conjunctions help connect two independent clauses correctly.
Here are three solid ways to fix a comma splice:
- Add a coordinating conjunction after the comma:
The sun was setting, and we hurried home. - Replace the comma with a period to make two sentences:
The sun was setting. We hurried home. - Use a semicolon to link closely related clauses:
The sun was setting; we hurried home.
Each method is grammatically correct—the best choice depends on your intended rhythm and flow.
Why This Mistake Is So Easy to Miss
Comma splices often fly under the radar because they sound natural—especially when you read your writing aloud. The rhythm of two short sentences connected by a comma can feel conversational and familiar, mimicking the flow of everyday speech.
In casual writing or dialogue, comma splices sometimes slip by unnoticed, and even skilled writers use them intentionally to create a certain tone or pacing.
However, when these mistakes creep into formal writing or narration unintentionally, they can undermine clarity and professionalism.
Additionally, standard grammar checkers don’t always flag comma splices, making them harder to catch without a trained eye.
Bonus Tip – When Breaking the Rule Works
While comma splices are generally considered errors, skilled writers sometimes break this rule intentionally to create rhythm, voice, or dramatic effect—especially in dialogue or creative prose.
For example, in dialogue, characters might speak in short, clipped sentences connected by commas to mimic natural speech patterns:
“I don’t know, I just... I can’t.”
In narrative, a well-placed comma splice can speed up pacing or convey urgency:
The clock struck midnight, the city fell silent.
The key is intentionality—knowing the rule so you can break it deliberately, not by accident. When used thoughtfully, breaking this comma rule can add style and flavor to your writing.
The comma splice is a subtle but common grammar mistake that can sneak into even the most polished writing. While it often sounds natural, it disrupts the flow and clarity of your sentences, making your work feel rushed or unprofessional.
By learning to spot and fix comma splices—with conjunctions, periods, or semicolons—you can sharpen your prose and keep readers fully engaged. And remember, knowing the rule means you can break it intentionally when it suits your style.
With this knowledge, your writing will be clearer, stronger, and more enjoyable to read.