Commas Part 1: Five Common Uses for Commas

Thank you to Grammar Diva for this content.
Commas: The bane of a writer’s existence. Depending on where you look, there can be ten —  or tons  — of comma rules. However, there are two main rules: 1. Don’t use a comma unless you have a reason (rule) to use it. 2. Use a comma anyplace where not using one would result in confusion for the reader. Simple, huh?

The purpose of punctuation is to make for easier reading. Without punctuation the reader doesn’t know where the sentences end, where there is a pause, or when a character is speaking. However, some punctuation rules, particularly those regarding the comma, don’t really make reading a whole lot easier. They seem superfluous, but we are told to use  them anyway.

This post is Part 1 in a series of posts about using commas; it describes five of the most common uses for the comma.

1 A compound sentence contains two (or more) complete sentences connected with a conjunction. These connecting conjunctions include and, but, for, nor, or, so, yet. 

  • We studied for about an hour, and we didn’t feel as if that was long enough.
  • We studied for an hour, we watched an hour of television, and we studied for another hour. 

If you don’t use the conjunction, you need to use a semicolon. This construction is still considered a compound sentence.

  • We studied for an hour; we didn’t feel that was long enough.

If the two sentences are short, you don’t need the comma.

  • I watched TV and I went to bed.

If the second sentence isn’t really a complete sentence, do not use a comma. Usually what is missing is the subject of the second sentence.

  • We studied for about an hour and didn’t feel as if that was long enough.

2. The series comma is probably the most well-known use of a comma. Items in a series need commas to separate them. The comma before the and is optional. That comma is called the Oxford, or series, comma. I like it, but it is not necessary. Two things to remember: If you decide to use the Oxford comma, use it consistently within a piece of writing. Don’t alternate between using and not using it. The only exception is to put it in when the meaning of the sentence would be confusing without it — even if you have not been using it in that piece of writing.  

  • This recipe calls for apples, pears, cranberries, and walnuts for the filling. (Oxford comma used.)
  • This recipe calls for apples, pears, cranberries and walnuts for the filling. (No Oxford comma.)
  • The dog ran out of the kitchen, into the yard, across the street, and over the fence. (A series of phrases.)
  • The dog ran out of the kitchen, into the yard, across the street and over the fence. (No Oxford comma.)
  • I went into the kitchen, I put the steak in the oven, and I washed the dishes. (Series of sentences – compound sentence.)
  • I went into the kitchen, I put the steak in the oven and I washed the dishes. (No Oxford comma.)

3. Commas are used in dialog to separate it from the rest of the sentence.

  1. She said, ” I don’t like the rain.”
  2. “I don’t like the rain,” she said.
  3. “I don’t like the rain,” she said. “I wish it would stop.”
  4. “I don’t like the rain,” she said, “and I wish it would stop.”

4. Use commas before and after etc. (and so on), i.e. (that is), and e.g. (for example).(Don’t forget the periods.)

  • You can make a fruit salad with any fruit: apples, oranges, pears, berries, etc.
  • I knit socks, sweaters, scarves, etc., for my grandchildren who live in a snowy climate.
  • She is the captain of the cheerleading squad, i.e., the leader of the cheers.
  • You need to take advanced math, e.g., calculus, to get into that school.

5. Salutations and closings of letters and e-mails use commas.

  1. Dear Frank,  (but in a business letter, a colon is more commonly used: Dear Ms. Symes:)
  2. Sincerely Yours,