Run-ons

Run-ons are two or more independent clauses joined incorrectly either with a comma or without punctuation.

There are two kinds of run-ons:

1. Fused Sentences join two or more independent clauses incorrectly without any punctuation or a conjunction.

There was a lot of ice on the road I slipped.
This fused sentence joins two independent clauses incorrectly without any punctuation. Each of these independent clauses can stand alone (“There was a lot of ice on the road” and “I slipped”).

2. Comma Splices join two or more independent clauses incorrectly by adding a comma.

The school is empty, there must be a snow day.
This sentence joins two independent clauses incorrectly with a comma. Each of these independent clauses can stand alone (“the school is empty” and “there must be a snow day”).

There was a lot of snow, however the school stayed open.
This sentence joins two independent clauses incorrectly with a comma and a conjunctive adverb. Conjunctive adverbs (however, nevertheless, moreover, etc.) should be preceded by a period or semi-colon and followed by a comma when used to join sentences. Each of these independent clauses can stand alone (“there was a lot of snow” and “the school stayed open”).

How to Revise Run-ons

Problem Sentence: There were five inches of snow, the trains stopped running.

1. Use a Comma and Coordinating Conjunction
Add a comma and a coordinating conjunction (and, but, or, nor, for, so, yet). Remember: the comma must precede the coordinating conjunction. There were five inches of snow, and the trains stopped running.

2. Create Separate Sentences
Separate independent clauses into two or more sentences by adding a period.

There were five inches of snow. The trains stopped running.

3. Use a Semicolon
Add a semicolon to separate two independent clauses. This is a good approach if there is a direct relationship between the two sentences. You might add a conjunctive adverb (however, nevertheless, moreover, etc.) after the semicolon to clarify the relationship between the sentences.

There were five inches of snow; consequently, the trains stopped running.

4. Use a Colon
Use a colon to fix a run-on if the first independent clause introduces the second or if the second gives a reason for the first.

The trains stopped running: there were five inches of snow.

5. Restructure
Restructure sentences into combined subordinate and independent clauses. (A subordinate clause begins with a subordinating conjunction, such as after, although, because, since, while, etc.)

Since there were five inches of snow, the trains stopped running.

Revision Checklist

Identify:
o Underline the main verb(s) in the sentence. Is there more than one main verb?
o Underline the subject for each main verb in the sentence. Is there a subject for each main verb?
o If there is a subject for each main verb, ask yourself, how are these parts joined? If there is proper punctuation, you have a compound or complex sentence. If there is no punctuation, or incorrect punctuation (like a comma splice), you have a run-on.

Fix:
o If you are joining two independent clauses with a coordinating conjunction, ask yourself, did I insert a comma before the conjunction?
o If you are separating a run-on into two sentences by inserting a period, ask yourself, can both of these clauses stand alone? o If you are joining two independent clauses with a semicolon or colon, ask yourself, is there a direct relationship between the two clauses? Do I need a conjunctive adverb to help clarify the relationship?
o If you are restructuring the sentence by creating an independent and subordinate clause, ask yourself, did I introduce the subordinate clause with a subordinating conjunction?

Where in The Bedford Handbook? See Section 20: Revise Run-On Sentences