Ways of Correcting Run-on Sentences

Definition

In prescriptive grammar, two independent clauses that have been run together without an appropriate conjunction and/or mark of punctuation between them.

Run-on sentences aren't always excessively long sentences, but they can be confusing to readers because they tend to express more than one main idea without making clear connections. (See sentence length.)

Usage guides commonly identify two kinds of run-on sentences: fused sentences and comma splices.

Exercises

Four Ways of Correcting Run-on Sentences

Run-on Sentences:
- Adam is a sweet boy he really loves animals.
- Adam is a sweet boy, he really loves animals.
To correct a run-on sentence, make it into two simple sentences. Put a period at the end of the first subject and verb group. Start the second sentence with a capital letter.
Correct Sentences:
Adam is a sweet boy. He really loves animals.
(Jill Singleton, Writers at Work: The Paragraph. Cambridge Univ. Press, 2005)
Sometimes two sentences are very closely related in meaning and full end-stop punctuation may seem too strong. A semicolon can then be used to divide the two sentences. . . .
Run-on: It was a beautiful day there was not a cloud in the sky.
Correct: It was a beautiful day; there was not a cloud in the sky.
(Phil Pine, Master the SAT 2008. Peterson's, 2007)

A run-on sentence can sometimes be prevented by using a comma and joining word (coordinate conjunction) to join sentences together.
Wrong: John went to the movies x Sue stayed home.
Correct: John went to the movies, and Sue stayed home.
(Christopher Smith et al., How to Prepare for the GED. Barron's, 2004)
"[Another way to correct a run-on sentence is to] change the run-on to a complex sentence by placing a subordinating conjunction before one of the clauses:
Run-on: I don't play tennis well I have a poor backhand.
Correct: I don't play tennis well because I have a poor backhand.
(P. Choy and D.G. Clarke, Basic Grammar and Usage. Cengage, 2005)

Run-ons and Comma Splices
"The presence or absence of a comma--and therefore the distinction between a run-on sentence and a comma splice--isn't usually noteworthy. So most writers class the two problems together as run-on sentences.

"But the distinction can be helpful in differentiating between the wholly unacceptable (true run-on sentences) and the usually-but-not-always unacceptable (comma splices). That is, most usage authorities accept comma splices when (1) the clauses are short and closely related, (2) there is no danger of a miscue, and (3) the context is informal. Thus: 'Jane likes him, I don't.' But even when all three criteria are met, some readers are likely to object. And in any event a dash seems preferable to a comma in a sentence like that one."
(Bryan A. Garner, The Oxford Dictionary of American Usage and Style. Oxford University Press, 2000)