A series is a list of words. Use a comma after each word in a series except the last word.
Ms. Pinckney asked Alonzo, Erica, and Charley to work on the project together.
Dakota put a sandwich, an apple, and a granola bar in her lunchbox.
Our neighbors have two dogs, three cats, seven chickens, and a goat.
Dakota put a sandwich, an apple, and a granola bar in her lunchbox.
Our neighbors have two dogs, three cats, seven chickens, and a goat.