Using commas is one of those grammatical issues that confuses a lot of people. There are many different scenarios that dictate when you should use commas. Most people get some of the simple comma rules correctly, but after those, there is a great deal of difference in how they are used. There are clear rules for correct comma usage, but too many people don’t know all of them.
One of the big problems with learning correct comma usage is that so may people get it so wrong. When you’re reading something from a professional writer, it’s safe to assume you are seeing the correct usage of commas. However, when you’re reading something from your friends, family or co-workers, it’s pretty likely that at least some of their comma usage is incorrect. Unfortunately, every time you see commas used (or not used) incorrectly, that makes it more confusing to separate the correct comma usage from the incorrect.
Here are some of the most commonly used rules for correct comma usage.
Separate words shown as a list.
Example: dogs, cats, turtles, fish and birds
However, if the different adjectives combine to show a single thought, commas should not be used.
Example: A majestic bald eagle is held in the highest regard.
To set apart clauses and phrases that are not essential to the sentence.
Example: The dog, who is sometimes a little freaky, was sleeping on the end of the sofa.
To separate phrases (or words) that are in opposition to a noun.
Example: The original Superman movie, from 1978, starred Christopher Reeve.
However, if the appositive phrase is considered essential, you should NOT use commas.
Example: The Christopher Reeve movie Superman is from 1978.
To set apart terms that are considered an interruption of the thought.
Example: The dog, of course, was sleeping. By the way, I won’t be home for dinner tonight.
To set off a phrase when you are addressing someone directly
Example: Did you like the movie, David?
To separate a phrase/word at the beginning of a sentence that is intended as an introduction.
Example: Several years ago, they met for the first time at the hot dog cart.
To separate a question within the sentence. This is called a tag question.
Example: You’re not going to the movie for the second time, right?
The final rule we will review related to correct comma usage is to use common sense. If there are multiple elements in a sentence that would be confusing if they were read together, you should use a comma to make it easier for the reader to understand what you are saying.
Example: As they walked into the house, in the shadows they missed the person who was lurking.
Of course, getting comma placement is only one of the important aspects of putting something in writing. If you are going to go through the trouble of writing something, you should take a few moments t make sure you’re following the proper rules of capitalization, italics and other basic grammar principles. It’s also important to find a good online spell checker. These are so easy to use that there is simply no excuse for not taking a few extra moments to spell check your document.