This article covers when to use a comma in communications.
After a sentence's introductory phrase
Use a comma after a sentence's introductory phrase.
Examples:
- When your computer makes a soft whirring noise, begin to open programs and applications.
- Because computers also can get tired, your computer may need a good cup of coffee to really start working well.
- In the beginning, listen to your computer and attend to what it seems to be asking for.
Do not use to separate info at the end of a sentence
Do not use commas to separate the same chunks of information when they appear at the end of a sentence.
Examples:
- Begin to open programs and applications when your computer makes a soft whirring noise.
- Your computer may need a good cup of coffee to really start working well because computers also can get tired.
- Listen to your computer and attend to what it seems to be asking for in the beginning.
Coordinating conjunctions
Use commas with a coordinating conjunction (FANBOYS) to combine two complete sentences on either side of the FANBOYS.
FANBOYS = for, and, nor, but, or, yet, so
Examples:
- The computer didn't want to start up this morning, but it did begin to work well after lunch.
- The computer needed to be updated, for it had only been updated once in five years.
- The computer also needed to be plugged in so that it could function.
- "That it could function" is not a complete sentence. Therefore, no comma is used before so.
Oxford comma (Series comma)
Use the Oxford comma to separate items of three or more in a list.
- The computer came with a mouse, monitor, and a power supply.
- To operate the computer, I had to plug in the mouse, hook up the monitor, and connect it to the power supply.
Parenthetical parts of a sentence
Use commas to separate parenthetical parts of a sentence. This comma guideline is often where extra commas sneak into the writing because the author thinks a pause is needed. Remember that the punctuation mark is needed for clarity and understanding more than anything else. Technical writing style doesn't often call for some of the more subjective times when you have to decide on the use of a comma or not.
- There are certain parenthetical parts that are more clearly defined, including dates, times, and city/state combinations:
- Begin by driving to Oskalousa, Iowa, to find the best computer repair shop.
- The computer repair shop is open on Monday, September 15, from 8 a.m. until 9 p.m., for the general public.
- There are also certain parenthetical parts that are clearly interrupting the sentence and are non-essential to the meaning of the sentence or helped by commas to add emphasis.
- The computer repair person, who sometimes comes to work dressed up like a video game character, will take excellent care of your computer.
- Your computer, thankfully, will get back to you in tiptop shape within 24 hours.