II. Grammar and Punctuation

2.2 Run-on Sentences

Run-on Sentences

Occur when two independent clauses are run together without an adequate indication of the break between them.

(An independent clause is a word group that could stand alone as a sentence):

He laughed. She cried. They were made for each other.

Fused Sentence

A fused sentence occurs when two independent clauses are run together with no punctuation to make the break between them:

He laughed she cried.

Comma Splice

A comma splice occurs when two independent clauses are run together with only a comma to separate them:

He laughed, she cried.

(A comma alone is not enough to separate independent clauses.)

When two independent clauses appear in one sentence, first decide if you want to keep them in the same sentence.

Your thoughts may be more clear if you separate them into two sentences:

Bob’s surgeon said he couldn’t get enough double cappuccinos, that made Bob nervous. (splice)

Bob’s surgeon said he couldn’t get enough double cappuccinos. That made Bob nervous. (correct)

If you decide to keep both in the same sentence:the clauses must be separated in one ofthese four ways:

with a semi-colonwith a comma and a coordinating conjunctionwith a semi-colon, a conjunctive adverb, and

a commaby subordinating one of the independent

clauses

With a semi-colon:

Bob’s surgeon said he couldn’t get enough double cappuccinos; that made Bob nervous.

With a comma and a coordinating conjunction:

Bob’s surgeon said he couldn’t getenough double cappuccinos, and thatmade Bob nervous.

With a semi-colon, a conjunctive adverb, and a comma:

Bob’s surgeon said he couldn’t getenough double cappuccinos; therefore,Bob felt nervous.

By subordinating one of the clauses:

When Bob’s surgeon said he couldn’tget enough double cappuccinos, thatmade Bob nervous.

Sample Sentences

Identify any run-ons among the following, and indicate how to correct the error.

1. Bob met Alyssa in a laundromat, he borrowed her bleach.

Splice

Separate into two sentences or subordinate one clause:

Bob met Alyssa in a laundromat. He borrowed her bleach.

Bob met Alyssa in a laundromat, where he borrowed her bleach.

2. She handed him her cell number on the way out, he called her from the pay phone.

Splice

Add the conjunction “and” after the comma:

She handed him her cell number on the way out, and he called her from the pay phone.

3. In front of her house, Bob noticed that her mailbox was lying on its side the screen door had been violently ripped from its hinges.

Fused

Add a comma and “and” after on its side:

In front of her house, Bob noticed that her mailbox was lying on its side, and the screen door had been violently ripped from its hinges.

4. She smiled sweetly, “My ex-boyfriend Bruno has a temper.”

Splice

Separate into two sentences by putting a period after sweetly or add the phrase “and said”:

She smiled sweetly. “My ex-boyfriend Bruno has a bit of a temper.”

She smiled sweetly and said, “My ex-boyfriend Bruno has a bit of a temper.”