Run-on sentences are sentences with "signal" problems. Readers look for punctuation to signal the end of one independent clause and the beginning of another.  Without appropriate punctuation readers are forced to determine the correct relationships, or else abandon the text altogether out of frustration. There are three variations of run-on sentences: sentences that use only a comma to join independent clauses, or "comma splices," sentences without any punctuation at all connecting independent clauses, or "fused sentences," and sentences that are simply joined by coordinating conjunctions like "and," without a comma.  If a writer wants to be heard, she must be able to tell the reader how her ideas go together.

In this module students will learn

• to recognize and correct run-on sentences
• to use colons, semi-colons, coordinating conjunctions and sentence adverbs appropriately

 

Correcting Comma Splices

A comma splice occurs when a comma is used without a coordinating conjunction to join two independent clauses together, as in the following sentence:

comma splice: There is time to finish the project, we won't finish it if we go to the beach, however.

Stronger punctuation is needed to connect two independent clauses.  We can use a semi-colon if the logical connection between the statements is clear:

corrected: There is time to finish the project; we won't finish it if we go to the beach, however.

We can also use a comma and a coordinating conjunction (and, or, for, nor, but, so, or yet) to connect two independent clauses. This is a good choice if the relationship between the clauses is unclear or needs emphasis:

corrected: There is time to finish the project, but we won't finish it if we go to the beach.

Separating the two clauses into two independent sentences with a period is always an option.  Note, however, that a period creates stronger separation between ideas than the other options. 

corrected: There is time to finish the project. We won't finish it if we go to the beach, however.

Rewriting the sentence to turn one independent clause into a dependent (or subordinate) clause is another option:

corrected: There is time to finish the project although we won't finish it if we go to the beach.

Often comma splices occur when the second clause begins with "this," "these," "that," or "those"; pay close attention to your sentence structure whenever you see these pronouns in your writing:

comma splice:  The drive from San Francisco to Los Angeles takes six-seven hours, this is a long and boring drive all by yourself. 

corrected:  This drive from San Francisco to Los Angeles takes six-to seven hours; this is a long and boring drive all by yourself.

 

 

Correcting Fused Sentences

Sentences are said to be "fused" when there is no punctuation connecting independent clauses.  A coordinating conjunction may be present in a fused sentence, but without an accompanying comma, the punctuation is still inadequate.

examples:

fused sentences:

I ate the whole pizza it was excellent.

On our trip to Los Angeles, we spent two days at Disneyland with the kids and they were the best days of the whole vacation.

I am going to get the new Gwen Stefani CD but you can borrow it any time.

Use the same techniques for correctin fused sentences as you would use to correct comma splices (as described in the previous section).

corrections:

I ate the whole pizza; it was excellent.

On our trip to Los Angeles, we spent two days at Disneyland with the kids, and they were the best days of the whole vacation.

I am going to get the new Gwen Stefani CD, but you can borrow it any time.