What is a Run-on Sentence?
A run-on sentence joins two or more independent clauses without the punctuation or conjunction that should connect them. It is called a "run-on" because one sentence runs into the next with no proper stop.
The Two Kinds of Run-on
- Fused sentence: no punctuation at all. "The results were clear the hypothesis was supported."
- Comma splice: only a comma. "The results were clear, the hypothesis was supported."
A Long Sentence Is Not Always a Run-on
Length does not decide. "Although the sample was small and drawn from a single university, the results, which were consistent across both rounds of testing, support the hypothesis" is long but correct: it has one main clause and properly attached parts. "I ran it failed" is short and is a run-on.
How to Check for a Run-on
- Find every subject and verb pair: each pair is a clause.
- Ask whether each clause could stand alone as a sentence.
- If two such clauses meet with nothing, or only a comma, between them, it is a run-on.
How to Fix a Run-on Sentence
- Full stop: "The results were clear. The hypothesis was supported."
- Semicolon: "The results were clear; the hypothesis was supported."
- Comma and conjunction: "The results were clear, so the hypothesis was supported."
- Subordination: "Because the results were clear, the hypothesis was supported."
Run-ons, Fragments and Comma Splices
A run-on has too much for one sentence; a fragment has too little. Both come from losing track of the clauses, and both are fixed with the right punctuation.
Tips
- Watch for "however", "therefore" and "then" after a comma: they often mark a run-on.
- Read your draft aloud and pause only where the punctuation tells you to.
- Vary your fixes, so your sentence structure does not become a string of short sentences.