Let’s Not Compound the Error

by Cherie Tucker

December 2015

It seems that we always have trouble with those pesky little commas. In a recent edit of student papers, I discovered that apparently the functions of commas in compound sentences are no longer being taught. They were universally absent in all 30 papers I had to grade.

So to review: A compound sentence is a sentence in which there are two independent clauses (a subject and a verb making a complete statement that can stand alone). For example:

Bill went to the store, but he forgot to bring his wallet.

Each part of that sentence could be written by itself:

Bill went to the store.

He forgot to bring his wallet.

Then they were joined by one of the FANBOYS (remember those: For, And, Nor, But, Or, Yet, So), which made them into a single, compound sentence. That joining also requires a comma before the “but” to show the reader that the first half is over, but the sentence is not.

In addition to the comma/FANBOY connection, compound sentences can be punctuated with a semicolon, which also alerts the reader to the end of the first part of the sentence but indicates that there is more to come that is related. There may be a transitional expression there, like however or therefore, to help the reader along.

Bill went to the store; however, he forgot his wallet again.

A compound sentence can also be written without a transitional expression by simply using the semicolon.

I tried a new recipe for Red Velvet cake; it didn’t work.

If you punctuate your compound sentence properly, your reader will not have to go back to figure out what you meant to say.

Cherie Tucker, owner of GrammarWorks, has taught writing basics to professionals since 1987, presenting at the PNWA conference.  She currently teaches Practical Grammar for Editors at the University of Washington’s Editing Certification program and edits as well. GrammarWorks@msn.com.