Five Rules for Comma Use

1. put a comma before FANBOYS coordinators (for, and, but, or, for, nor, so, yet) when they connect two complete sentences (independent clauses).

I hate Mondays, but I love Fridays.

I hate Mondays but love Fridays.

2. Put a comma between each item in a series.

He likes cake, ice cream, and turnips.

He ate dinner, felt sick, and looked for the Pepto-Bismol.

Some words "go together" and don't need commas: dear little old lady; dilapidated old building.

Dates and addresses in sentences are like lists:

Olive lives at 213 Pimento Drive, Santa Fe, New Mexico.

She was born January 23, 1923.

3. Put a comma after an introductory expression that does not flow smoothly into the sentence--a word, group of words, or dependent clause.

No, I don't want any.

Rushing to the door, she dropped the pizza.

After that, we left.

During the party, we ate a lot of food.

At 10:00, she called him.

While they were sleeping, the phone rang.

If you don’t study hard, you’ll fail your classes.

Because of her mistrust, she wouldn’t tell him anything.

Ten years ago, we moved here.

4. Put commas around nonessential material--material that the sentence could survive without.

Gladys, who loves to ice skate, broke her toe.

The house, which we painted last week, is for sale. (we won’t know which house it is unless we have the information within the commas)

5. Don’t put a comma between two complete sentences (I was hungry, I ate cake). That’s a comma splice, and that’s incorrect.

Practice Exercise: Add punctuation to the following sentences (commas and/or periods). Fix capitalization if necessary.

  1. She needed money so she went to the bank.
  2. She lived in Seattle she worked at Highline
  3. If you need money you can go to the bank
  4. At most colleges there are a wide variety of majors to choose from
  5. Don’t forget to do your homework if you do you will not get any points
  6. We have a cat and we have a dog
  7. Three years from now I hope to get my BA degree.
  8. There are a lot of steps to succeed in college first of all you have to study hard
  9. In the middle of the night it started to rain my husband got up to shut the windows
  10. My advisor told me I could take Writing 101 now or I could take it later it was my decision