Run-On Sentences Explained (and Fixed!)

ByDylan Callens

Run-On Sentences Lesson: Teach students to recognize run-on sentences, including fused sentences and comma splices. Students use periods, semicolons, or commas with coordinating conjunctions to create readable revisions.

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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:

  1. 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.

Student Worksheet

Answer Key

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.

Back to the Grammar Lessons

Apply and Extend This Grammar Skill

Exit ticket: Fix “We finished the project, we handed it in” in two different ways and explain the punctuation.

Next lessons: compound sentences · comma rules. Explore the complete Grammar Lessons hub.

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