The Quick and Easy Guide to Commas

Do Commas Give You Pause?

It seems that most writers struggle with commas. We worry about using too many or too few. We aren't sure when the comma is required, optional or unneeded. We waver between the "breath" rule and "when in doubt, leave it out." Adding to this anxiety is the variety of editing styles writers face. Is there an easy way to know when to use and when not to use the comma? I think so. While it may not cover every situation, this document is meant to give writers a simple guide to common comma usage.

Major Uses of Commas:

After an introductory clause or phrase, use a comma. However, the comma is optional if the introduction is very short.

Examples:

Before you begin the project, please review the guidelines.
As we are in a hurry, promptness would be appreciated.
Tomorrow we will contact your supervisor.

Use commas to set off transitional phrases; for example, phrases that include "however," "therefore," "for example" and "in other words." Only use commas with transitional phrases at the beginning and middle of sentences.

Examples:

The cost of the part, as estimated by the contractor, is within our budget allowance.
However, William was unable to find time to make the repairs.
This has caused a major delay; therefore, the product release date has been postponed.

Commas separate items in lists, inventories, and rosters used in a sentence. If your items are grouped (e.g., Laurel and Hardy), use the comma to set apart the group. The comma before the final conjunctive "and" is optional. Use it if it helps the reader. Do not use the comma before the first item or after the last item of a list.

Examples:

The new technician is responsible for set-up, operation and quality control.
Training, evaluation and feedback are her supervisor's responsibility.
Her orientation includes meetings with Personnel, Research and Design, and Operations.

Use commas to set off parenthetical or non-essential information, which may be adjective clauses and phrases, or appositives. However, if the clause or phrase significantly changes the meaning of the sentence, do not use a comma.

Examples:

The contract, which was signed this week, gives the company full ownership of the film.
We have already had several meetings with Steven Spielberg, the director of the film.
The filming schedules, with photographs of locations, are included in your packets.

Commas should be used with conjunctions to join independent clauses, but they should not be used with dependent clauses. Sentences with very short independent clauses may not need a comma.

Examples:

I received your offer this week, and you can expect my written answer very soon.
The starting date was not listed in your letter, but I assume you need someone immediately.
I will call you next week or you can leave a message with my service.

"Quotations, dates, addresses, and numbers," he stated, "All require the use of commas."

Example:

"On February 19, 1999, we began the investigation," answered the inspector. "We entered the premises at 40 South Grant Avenue, Beaverton, Oregon, at 2 pm. There we found approximately $200,000 in cash."

Other Comma Usage

There are other cases requiring commas. For a complete guide to comma usage, see The Bedford Handbook for Writers, or any other good grammar handbook.

Brevity, the Soul of Good Writing

In many of the examples given above, using a simpler sentence structure could eliminate confusion for the writer and reader. For example, independent clauses can be correctly joined to form a compound sentence. But it may be more effective to write the clauses as separate sentences. Choosing the simpler method usually makes your document easier for your reader to understand. And this is really the point of good writing, isn't it?