What Is Run-On Sentence? Definition, Examples & Tips
Clear Definition
A run-on sentence occurs when two or more independent clauses (complete sentences) are joined without proper punctuation or coordinating conjunctions. In plain language, it's when a writer connects thoughts without the pauses or links a reader needs to follow along.
Understanding what is run-on sentence helps you spot where to add a period, semicolon, or conjunction to clarify meaning. Fixing run-ons improves readability and prevents misinterpretation.
Examples
Below are common run-on examples with corrected versions so you can see the fixes in context.
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Run-on: I finished my homework I went out to play.
Fix: I finished my homework. I went out to play. -
Run-on: She wanted to join the team she didn't have the time.
Fix: She wanted to join the team, but she didn't have the time. -
Run-on: The sun rose the birds started singing everyone smiled.
Fix: The sun rose; the birds started singing, and everyone smiled.
Common Errors
Writers make run-on mistakes for several reasons. Below are the most common errors and quick techniques to correct them.
- Missing punctuation: Two independent clauses are placed side-by-side without a period, semicolon, or comma + conjunction. Fix by adding one of these options.
- Comma splice confusion: Using only a comma to join two full sentences (e.g., She left, she was late). Either replace the comma with a period or add a coordinating conjunction (for, and, nor, but, or, yet, so).
- Overly long sentences: Small ideas get chained into one sentence. Break long sentences into 2–3 shorter ones to improve clarity.
- Ignoring clause boundaries: Treating dependent clauses as independent or vice versa. Identify subjects and verbs to check clause type before connecting them.
Quick fixes you can use now
- Replace a weak join with a period: "A. B."
- Use a semicolon to link related ideas: "A; B."
- Add a coordinating conjunction with a comma: "A, and B."
- Convert one clause into a subordinate clause: "Because A, B."
Actionable tip: When you finish a draft, read sentences aloud. Natural pauses often indicate where punctuation is needed.
Related Terms
- Comma splice: A specific run-on where two independent clauses are joined only by a comma. Example fix: change to a period or add a coordinating conjunction.
- Fused sentence: A run-on in which independent clauses are joined with no punctuation at all. The fused sentence needs obvious separation.
- Independent clause: A group of words with a subject and verb that can stand alone as a sentence. Run-ons occur when multiple independent clauses are joined incorrectly.
- Sentence fragment: The opposite problem — an incomplete sentence that lacks a main clause. Aim for complete sentences without creating run-ons.
If you write a lot, consider using tools to catch run-ons and related mistakes. Rephrasely's AI writer (Composer) can help draft clear sentences, while the paraphraser can suggest shorter alternatives. After editing, run the text through the AI detector or plagiarism checker for confidence, and visit Rephrasely for the full suite of writing helpers including a translator and grammar tools.
Frequently Asked Questions
How do I tell if a sentence is a run-on?
Check for multiple independent clauses without proper separation. If you can split the sentence into two or more complete sentences that make sense on their own, it's likely a run-on. Read aloud to sense missing pauses.
Can I use semicolons to fix run-on sentences?
Yes. Use a semicolon to join closely related independent clauses: "She studied all night; she passed the exam." Use semicolons sparingly and only when the clauses are closely connected.
What quick habit prevents run-on sentences?
Pause after each clause when you read your writing aloud. If you naturally pause and the sentence keeps going, consider adding a period, semicolon, or conjunction. Regularly revising with tools like Rephrasely's Composer and paraphraser speeds improvement.