5.2 Commas with Items in a Series
You may be aware of the two ways of writing items in a series, with either a comma before and or no comma before and.
I ate the crackers with a banana, peanut butter, and jam.
I ate the crackers with a banana, peanut butter and jam.
The comma before and or another conjunction is known as the Oxford comma (because Oxford University Press uses it) or the serial comma. Opinions vary among writers and editors about whether this final comma should be used. It is more common in American English than in British English writing, but usage varies in the U.S. as well. The Chicago Manual of Style recommends its use, while The Associated Press Style Guide (and therefore most journalistic writing) says to avoid it, unless doing so results in ambiguity. Consider the following sentence:
I went to the LSA meeting with Anne, a linguist, and a horseback rider.
This is ambiguous, of course, because it is not clear whether a linguist is an appositive describing Anne, or is the second person in a list of three different people. When we remove the final comma, we lose the possibility that a linguist is an appositive, but still have the possibility that we have three separate people attending the meeting.
I went to the LSA meeting with Anne, a linguist and a horseback rider.
And we now have the possibility that Anne is both a linguist and a horseback rider, so there is ambiguity both with and without the final comma. We can, of course, change the wording to remove the ambiguity.
What do you think? Should we always keep the comma before and with items in a series to avoid the possibility of ambiguity? Or should we only put it in when the sentence could potentially be misinterpreted?
Semicolons are used to separate items in a series when those items contain commas. For example,
The meeting was attended by Ms. Sue Allen-Schmidt, professor of engineering; Mr. Jorge Rivera, director of marketing; and Ms. Jo Dorling, vice president of manufacturing.
[There are some pretty good online semicolon quizzes that your students might enjoy, after covering this lesson, and the one on semicolons in clauses (Lesson 5.3).]
key words: punctuation, commas, variation
CCSS.ELA-Literacy.L.5.2a Use punctuation to separate items in a series
Here is this lesson as a pdf.