Run-On Sentences Explained (and Fixed!)
Run-on sentences are one of those grammar issues that sneak into student writing when ideas are flowing faster than punctuation. Students often know what they want to say, but their sentences forget to stop. The result? Writing that feels rushed, confusing, or overwhelming to read.
The good news: run-on sentences are easy to fix once students know what to look for and which tools to use.
What Is a Run-On Sentence?
A run-on sentence occurs when two or more independent clauses are joined without correct punctuation or a connecting word.
Important note:
Run-on sentences are not about sentence length. A short sentence can be a run-on, and a long sentence can be perfectly correct.
Common Types of Run-On Sentences
Fused sentences
Two independent clauses are joined with no punctuation at all.
Example:
I like pizza I eat it every Friday.Comma splices
Two independent clauses are joined with a comma only.
Example:
I like pizza, I eat it every Friday.
How to Fix Run-On Sentences
Students have three reliable options:
Add a period
Turn the ideas into two separate sentences.Add a comma + coordinating conjunction
(for, and, nor, but, or, yet, so)Use a semicolon
When the ideas are closely related.
Corrected examples:
I like pizza. I eat it every Friday.
I like pizza, and I eat it every Friday.
I like pizza; I eat it every Friday.
Practice Together (Guided)
Fix the run-on sentence using any correct method:
The sun was setting we hurried home.
Possible answers (discuss together):
The sun was setting. We hurried home.
The sun was setting, so we hurried home.
The sun was setting; we hurried home.
👉 Emphasize that multiple correct answers are possible.
Practice Alone (Independent Work)
Students rewrite each run-on sentence so it is grammatically correct.
Conclusion: From Rushing to Clarity
Run-on sentences happen when ideas collide without clear boundaries. By teaching students to recognize independent clauses and choose the right fix, you give them control over their writing. Once they master this skill, their sentences slow down, their ideas become clearer, and their writing becomes much easier to read.
Run-ons don’t mean students are bad writers — they usually mean students have too many ideas, which is a problem worth fixing properly.
