Business Writing Essentials
How often do you put a period in the wrong place? Most likely never. Now ask yourself the same question about the comma. Most people think, "Of course I obey the rules about using the period, but the use of the comma is a subjective thing."
The problem with this reasoning is that there is nothing subjective about it for the reader. If your reader has to pause to figure out what it is you are saying, you may need to improve your use of the comma.
The most common problems in using (or not using) the comma are described below.
Introduce stuff: Use your ear to decide if a comma is needed after an introductory element. If you have any doubts about it, include the comma.
Clueless as always he broadcast the email.
Clueless as always, he broadcast the email.
Connect stuff: If two complete sentences are joined by a coordinating conjunction, always put a comma in front of the conjunction. If two complete sentences are joined by a comma, always include a coordinating conjunction after the comma.
Ann needed office supplies, there were plenty in the cabinet.
Ann needed office supplies, and there were plenty in the cabinet.
Coordinating conjunctions are and, but, or, yet, and so.
[memory aid: A-BOYS]
Exception: It's okay to not use the comma when the two sentences are both very short.
Bob broadcast the email, but Ben deleted the virus.
Bob broadcast the email but Ben deleted the virus.
Separate stuff: Always play it safe by putting a comma between every pair of elements in a series. The typical reason for not doing this is the complaint, "Journalists don't do it, so why should I?" Ask them why they do it and they will talk about tradition, not about clarity. You will never be unclear if you include all the commas.
Amy needed folders, pens and paper.
Amy needed folders, pens, and paper.
Note: Where the trouble started
Here's the truth: rules about using commas are not really rules, they're guidelines. If you say this near your seventh-grade English teacher, duck or brace yourself for a bit of ear twisting.
Arguments about the use the comma are as old as parchment. For several thousand years, marks that became the modern comma were used to show people reading out loud, or chanting, where best to pause or take a breath. Lately, five hundred years ago or so, they also took on the role of helping to decipher syntax and to decode meaning for those reading silently to themselves. These two uses for the comma have been at war ever since.
Ignore the war. Always start with the "rules" of using the comma. But if something else works better for your situation at work, it's okay to adapt (if your boss approves).
Course: Business Writing Essentials