Sentence Effectiveness
1. Run on Sentences
Definition
A run-on sentence occurs when two or more independent clauses are not joined correctly. An
independent clause is a group of words that can stand alone as a sentence, as in, “the dog runs.”
Your writing may be confusing or unclear if independent clauses are joined incorrectly.
There are two types of run-on sentences: fused sentences and comma splices.
A fused sentence occurs when independent clauses run together with no marks of punctuation or
coordinating conjunctions to separate them.
Fused sentence: My professor read my paper she said it was excellent.
independent clause independent clause
A comma splice occurs when two or more independent clauses are joined only by a comma.
Comma splice: My cat meowed angrily, I knew she wanted food.
independent clause independent clause
REVISE RUN-ON SENTENCES in one of four ways:
• Use a comma and a coordinating conjunction (and, but, yet, so, or, nor, for). When you
join two independent clauses with a coordinating conjunction, place a comma before the
coordinating conjunction.
Run-on: My professor read my paper she said it was excellent.
Correction: My professor read my paper, and she said it was excellent.
• Use a semicolon (or, in some cases, a colon or a dash). You can use a semicolon alone
or with a transitional expression (e.g., however, at any rate, in contrast, as a result, etc.).
Run-on: My cat meowed angrily, I knew she wanted food.
Correction: My cat meowed angrily; I knew she wanted food.
Correction with a transitional expression:
My cat meowed angrily; therefore, I knew she wanted food.
• Separate the independent clauses into sentences. This is an especially good
technique when one of the independent clauses is very long.
Run-on: It seemed to Wanda that her daughter had more than enough
crayons, they were strewn across the bedroom floor and
some of them were broken, and, worse still, someone had
used the stub of a red crayon to mark a sinister smiley face
on the wall.
Correction: It seemed to Wanda that her daughter had more than enough
crayons. They were strewn across the bedroom floor, and
some of them were broken. Worse still, someone had used the
stub of a red crayon to mark a sinister smiley face on the
wall.
• Restructure the sentence by subordinating one of the clauses. You can subordinate
a clause if one of the independent clauses seems less important than the other. Here
are a few examples in which one of the clauses has been subordinated (indicated here
by underlining). Note that a subordinated clause is no longer independent—it cannot
stand on its own as a sentence.
Run-on: The largest tree by volume in the world is the General
Sherman Sequoia, it is a little over 52,500 cubic feet.
Correction: The largest tree by volume in the world is the General
Sherman Sequoia, which is a little over 52,500 cubic feet.
Run-on: Toni Morrison is a professor at Princeton University, she
wrote the novel The Bluest Eye.
Correction: Toni Morrison, a professor at Princeton University, wrote
The Bluest Eye.
Run-on: I told my roommate I would be late, she still locked me out.
Correction: Although I told my roommate I would be late, she still locked
me out.
Run-on: I told the children I would read to them they said they
wanted to sit by me so they could look at the pictures.
Correction: When I told the children I would read to them, they said they
wanted to sit by me so they could look at the pictures.