Run-On Sentences: How to Spot Them and Fix Them Fast
Have you tried to read a sentence that just kept going and going and by the time you reached the end you forgot what it was even about but the commas kept dragging you along like a leash you didn’t sign up for?
Congratulations—you’ve just met a run-on sentence.
Run-ons aren’t complicated to fix, but they sneak in more often than you’d think. Let’s break down what they are, why they trip readers up, and how to fix them so your writing stays sharp.
What Is a Run-On Sentence?
A run-on happens when two (or more) complete sentences get jammed together without proper punctuation or a connecting word.
Run-On: “I finished my story I sent it to a contest.”
Fixed: “I finished my story, and I sent it to a contest.”
Also Fixed: “I finished my story. Then I sent it to a contest.”
The problem isn’t length—long sentences are fine. The problem is clarity. A run-on is basically two ideas driving through an intersection without a traffic signal.
Common Types of Run-Ons
1. The Classic Smash-Up
Run-On: “She opened the door it slammed in the wind.”
Fix: “She opened the door, and it slammed in the wind.”
2. The Endless Comma Train (a.k.a. Comma Splice)
Run-On: “He loved writing, he hated editing, he always procrastinated.”
Fix: “He loved writing, but he hated editing. He always procrastinated.”
3. The Speed-Talker Special
Run-On: “They left the cafe they caught the bus they went downtown they missed the movie.”
Fix: “They left the cafe, caught the bus, went downtown—and still missed the movie.”
How to Fix Run-On Sentences
Add punctuation. Split ideas with a period, semicolon, or em dash.
Use a conjunction. Words like and, but, so, yet connect ideas smoothly.
Break it into smaller sentences. Don’t be afraid of a period—it’s not a failure, it’s a breath.
Vary rhythm. Mix short and long sentences so your prose doesn’t feel like a marathon.
Takeaway
Run-ons happen when your sentences sprint ahead without guardrails. They’re easy to spot, and even easier to fix once you know what to look for.
Think of it this way: your reader needs road signs, not an endless road.
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