Commas are like people on the subway: You think you know them, but they're complex. This week, we'll dig deeper and get to know some of their jobs: separating items in a series (the Oxford comma), delineating appositives, and surrounding nonrestrictive phrases.
Commas are a workhorse punctuation mark. They’re like the people you ride with on the subway every day, the delivery guy who comes by your office, and the parents of your children’s classmates—you see them so often that you think you know them just from sheer exposure. Rarely does a paragraph go by in which you don’t encounter a comma. But like those familiar strangers, commas are complex. You might get a sense of them from casual observation, but to truly know them, you have to dig deeper.
Let’s get to know the comma a little better.
The Oxford Comma
Sometimes your subway buddy wears a suit with leather Oxfords and sometimes he wears jeans with Converse high-tops. His different activities call for different styles. So it is with the comma.
If you’re writing a nonfiction book, you need a tight-laced style: the Oxford comma. It’s orderly. It’s clear. Whoever told you the and takes the place of the comma was wrong.
The Oxford comma (the style recommended by Oxford University Press and Chicago Manual of Style) is the last comma in a series, the comma before the final and or or:
He wore a suit, a tie, and Oxfords.
He felt hot, sweaty, and tired.
If you’re writing something lighter—a press release or newspaper articles—you can get away with a more relaxed style: omit the Oxford comma. The Associated Press recommends against the Oxford comma, unless leaving it out will cause confusion.
He wore jeans, a T-shirt and high-tops.
He felt relaxed, cool and eager.
When might the Oxford comma be needed for clarity? Ponder the difference between these two examples:
We invited the jugglers, JFK, and Stalin.
We invited the jugglers, JFK and Stalin.
Next: Commas with Appositives and Nonrestrictive Phrases