In business writing courses, people always take sides on the use of commas with series. Known as the serial comma or the Oxford comma, this comma keeps us from running together items in a series.
He leads the symphonic band, the jazz band, and the orchestra.
Daisies, black-eyed susans, and coneflowers are blooming in the flower box.
Would you like iced tea, coffee, or something else?
I am on the side of those who use the serial comma the way I did above, with a comma before the conjunction and or or. Some people leave out that final comma.
But whose side do writing style guides favor?
Surveying the 11 current, respected style manuals and dictionaries on my bookshelf, here is what I found:
- 7 recommend including the comma before the conjunction.
- 2 (Merriam-Webster's Collegiate Dictionary and Canadian Oxford Dictionary) recommend the comma before the conjunction but acknowledge that some writers omit it.
- 2 (The AP Stylebook and The Canadian Press Stylebook) leave out the comma before the conjunction unless doing so would cause confusion.
If you are wondering how leaving out a comma might cause confusion, consider this example, whose source I have forgotten:
I dedicate this book to my parents, Ingrid and God. (Without the comma, the sentence suggests the author's parents are Ingrid and God.)
I dedicate this book to my parents, Ingrid, and God. (Here we know the parents are unnamed.)
People generally agree on these other comma rules for series:
1. Do not use a comma next to an ampersand.
Sign the card "With love from Anne, Jeffrey & Caroline."
2. Do not use a comma to separate items that are regarded as one unit, such as bacon and eggs.
The breakfast menu always includes cold cereal, oatmeal, bacon and eggs, and toast.
3. Do not use commas if all the items are separated by and or or.
She loves hip-hop and reggae and Latin jazz.
4. "As well as" is not the same as and structurally.
NOT THIS: We will visit New Orleans, Miami, as well as Dallas.
BUT THIS: We will visit New Orleans, Miami, and Dallas.
OR THIS: We will visit New Orleans, Miami and Dallas.
I like punctuation to be simple and straightforward. That's why I am on the side of always using the serial comma before the conjunction rather than using it only when the sentence might be confusing without it.
The editors of 9 of my 11 reference books agree with me. Do you? I welcome your comments, your suggestions, and your serial commas!
Test yourself on lots of punctuation and usage rules with my Error Quests booklet.