commas

NC State follows AP style with respect to comma usage. To quote the AP Stylebook: “Use commas to separate elements in a series, but do not put a comma before the conjunction in a simple series.”

• Correct: I’m taking courses in English, accounting and entomology.
• Incorrect: The cafeteria served pizza, lasagna, and salad.

However, if the final element of a series includes a conjunction, then to prevent confusion it’s best to put a comma before the concluding conjunction in the series.

• Correct: I had orange juice, toast, and ham and eggs for breakfast.

To ensure clarity, it’s sometimes appropriate to use a comma before the concluding conjunction in a series of complex phrases.

• Correct: We must ask ourselves whether the strategic plan meets the needs of current and future students, whether it can be implemented with the resources available to us, and whether its success can be accurately measured.

For further guidance on comma usage, refer to the “comma” entry in the AP Stylebook punctuation chapter.