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The Wrong Stuff:  Run-ons, Comma Splices, and Fragments


Good writers avoid run-on sentences, comma splices, and sentence fragments.  To do this, they use the correct punctuation to join two complete ideas or independent clauses.

First, you might need to refresh your memory about independent clauses.  An independent clause contains a complete idea expressed with a subject and a verb (and without the words that begin subordinate aka dependent clauses).  Every sentence has at least one independent clause. 

The Correct Ways to Join Two Independent Clauses:

  1. Independent clause , (comma) coordinating conjunction (and, or, but, for, so, yet, nor), independent clause    I went to the store, and she went to a friend's house.
  2. Independent clause ; (semicolon) independent clause     I went to the store; she went to a friend's house.
  3. Independent clause : (colon) independent clause    I went to the store I needed some milk.    [Use this when the second clause explains or gives an example of the first.]

When using a semicolon to join clauses, use a conjunctive adverb like however after the semicolon where you would normally use but.  
I wanted ice cream, but she wanted cotton candy.   I wanted ice cream; however, she wanted cotton candy.

What Happens When You Don't Join Them Correctly?  Bad Times!


Run-on Sentences

Many students come from the junior high thinking a run-on sentence is merely an extra long sentence, one that runs on and on.  How wrong they are!  That's probably why some grammar books use the term "fused sentence."  However, even that term isn't all that precise.  If I were king, I would decree that from henceforth the run-on sentence would be called the fender bender sentence.  See if you agree with my decree based on this information:  a run-on sentence occurs when one idea (independent clause) runs into another idea without appropriate conjunctions or punctuation. Fender bender works for me.  A second choice would be "the runs-into sentence."

I went to the store she went to a friend's house.  Call the cops!  Fender bender here!  One idea ran into another without the cushion of proper punctuation/conjunctions.  Somebody's insurance is going up, and their grade is going down.

Comma Splices

When you splice something, like electrical wires, you join them together.  In a sentence if you try to join two ideas with just a comma and leave out the coordinating conjunction, you're guilty of a comma splice. 

I went to the the store, she went to a friend's house.  How ugly is that?

Sentence Fragments

If you leave out a subject or verb, instead of a complete idea, you have just a piece or fragment of one.

Went to the store.  Went to a friend's house.  Without a subject, these are just fragments.  They happen often when  you answer a question in a lazy way.

Here's another way to have a sentence fragment:  having a dependent clause all by itself.  Since all clauses have a subject and a verb,  a dependent clause has both.  However, and ironically, even with both a subject and a verb, a dependent or subordinate clause does not express a complete idea.  By placing one additional word in front of the subject and verb combo, you create a dependent clause.

Because I went to the store.   When she went to a friend's house.  Both of these are fragments because when that one word was added, they lost the ability to express a complete idea and now must depend (hence the name dependent clause) on an independent clause to make sense.  Sometimes, more is less.  The because example happens a lot in response to Why...? questions.

Because I went to the store, I missed my favorite TV show.  When she went to a friend's house, she ate too much pizza.  These work because an independent clause is there for the dependent clause to lean on.  Dependent clauses are also called subordinate clauses because subordinate means of lesser importance or authority, and good writers place their important ideas in independent clauses and less important ideas in subordinate clauses. 

Clauses  Here you will find the words that can begin dependent (subordinate) clauses and more information about clauses.