How to Fix Run-On Sentences
A clear guide to identifying and correcting run-on sentences in your writing.
Spotting the problem in your own writing
Finding run-on sentence problems starts with knowing what two or more independent clauses joined with no punctuation or wrong punctuation looks like on the page. Once you can name the pattern, you start catching it in drafts before anyone else does.
A run-on sentence jams together two or more independent clauses with no punctuation or the wrong kind. A fused run-on has none; a comma splice is a type of run-on joined by a comma.
The good news is that most of these errors follow a small set of shapes. Learn the shapes and the fixes, and editing gets much faster.
Length alone does not make a run-on, the missing punctuation between clauses does, so check the joints of any long sentence.
After fixing several run-ons, vary your sentence lengths so the prose does not turn choppy.
A period is the simplest cure, but a semicolon or a subordinating word can keep related ideas together smoothly.
A coordinating conjunction with a comma, like and or but, keeps two related clauses together without fusing them.
What it looks like: wrong versus right
| Wrong | Right | Why it works |
|---|---|---|
| The code compiled. We ran the tests. | The code compiled we ran the tests. | The fix keeps the sentence clear and grammatical. |
| I was tired, so I went to bed. | I was tired I went to bed. | The fix keeps the sentence clear and grammatical. |
| She laughed; he did not. | She laughed he did not. | The fix keeps the sentence clear and grammatical. |
The quick fixes that almost always work
- Identify the exact word the error hinges on before changing anything.
- Apply the smallest fix that makes the sentence correct.
- Reread the whole sentence after editing, since one fix can shift meaning.
- When in doubt, rewrite the sentence in simpler structure.
Fixing run-on sentence step by step
- 1Find the subject and the verb
Locate the core words the sentence hangs on, since most of these errors live there.
- 2Name the mismatch
Decide exactly what is wrong before you touch the sentence.
- 3Choose the right fix
Pick the smallest change that resolves the error, from the options above.
- 4Read it back in context
Check the sentence in its paragraph to be sure the fix did not create a new problem.
Start with the most limited change that corrects the sentence. Big rewrites are sometimes needed, but small fixes are usually enough and safer.
Run-on sentence: the essentials
Building the habit
The fastest way to stop making run-on sentence errors is to check for them on a dedicated editing pass rather than while you draft. Writing and fixing are different jobs, and they work better apart.
Run a grammar checker over the draft to catch what your eye misses, but always confirm its suggestions, since automated fixes get agreement cases and style wrong now and then.
Over time, spotting run-on sentence becomes automatic, and your first drafts come out cleaner.
A period is the simplest cure, but a semicolon or a subordinating word can keep related ideas together smoothly.
Length alone does not make a run-on, the missing punctuation between clauses does, so check the joints of any long sentence.
After fixing several run-ons, vary your sentence lengths so the prose does not turn choppy.
Run-on sentence errors are easy to fix once you can see them. The real skill is learning to look for them before someone else has to.
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