by Jennie Ruby
Four kinds of interruptions to a sentence need commas: contrary negative interruptions, independent comments, transition words and nonessential descriptions. Let's look at contrary negatives and independent comments first.
Contrary negatives usually begin with but not or just plain not.
Here are examples:
- The backspace key, not the delete key, deletes the previous character.
- Bicycles, roller blades, and roller skates, but not skateboards, are allowed in this section of the park.
Independent comments tell the reader extraneous information about the sentence:
- Tea drinkers, we all agreed, use more sugar than coffee drinkers.
- "I disagree," he said, "I think coffee drinkers use more sugar."
- The dialog box on the left, as you can see in the screen shot below, has more options.
Transition words (however, therefore, moreover, nonetheless, hence, nevertheless, thus) need commas before and after when they are interrupting in the middle of one sentence. But be careful, because sometimes they appear between two sentences and require a semicolon before and a comma after.
Here is a transition word interrupting a single sentence:
- He drinks black coffee every morning. I, however, prefer tea.
Here is a transition word between two sentences:
- He drinks black coffee every morning; however, I prefer tea.
You could, of course, put a period at the end of the first sentence and have the transition word at the beginning of your second sentence (of course, is, of course, an independent comment):
- He drinks black coffee every morning. However, I prefer tea.
The final kind of interruption with commas is the nonessential description. It is nonessential because if you left it out, the reader would not be left wondering who or what you are talking about.
Here are examples of nonessential descriptions:
- The Potomac River, which is tidal at the point where it passes the Wilson Bridge, is much cleaner now than it was in the 1970s.
If you removed the part about being tidal, the reader would still know which river you were talking about. Here is another nonessential description:
- The Microsoft Word chart applet, which is included at no extra cost with the Word program, is robust enough to handle basic charts.
What all of these interruptions have in common is that they could be removed from the sentence with no major loss of meaning. These interruptions add detail, explanations, and extraneous information, or they clarify the relationships between parts of a sentence. Next time we will look at interruptions with no punctuation at all.
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About the Author: Jennie Ruby is a veteran IconLogic trainer and author with titles such as "Editing with Word 2003 and Acrobat 7" and "Editing with MS Word 2007" to her credit. Jennie specializes in electronic editing. At the American Psychological Association, she was manager of electronic publishing and manager of technical editing and journal production. Jennie has an M.A. from George Washington University and is a Certified Technical Trainer (Chauncey Group). She is a publishing professional with 20 years of experience in writing, editing and desktop publishing.