commas in lists
Commas that separate the items in a series of words, phrases, or clauses.
Separate three or more items in a list with commas: The drawer contained receipts, envelopes, and stamps. The items can be phrases: She checked the windows, locked the doors, and switched off the lights. The comma before the final and or or is the Oxford comma; see that entry.
Two items joined by and or or take no comma: Bring your passport and boarding pass. An item can contain several words and still be one item: The fee covers registration and access to the online archive.
When an item is itself a pair, it is a compound item. Put the commas between the compound items, not inside them: The café serves soup and bread, fish and chips, and fruit and yogurt.
Do not put a comma after the final item: The maps, receipts, and photographs were in the folder. A comma after photographs would separate the subject from its verb.
When the items contain commas of their own, separate the items with semicolons: The speakers were Lena Ortiz, a surveyor; Marcus Bell, an architect; and Priya Shah, a planner.
See also comma; Oxford comma; comma between subject and verb; semicolon.
Examples
UseWe need someone to prepare the agenda, record the decisions, and circulate the minutes. (Commas separate the three items in the list.)
UseThe package includes breakfast and dinner. (Breakfast and dinner is a pair, not a list, so it takes no comma.)
UseThe morning sessions cover reading and writing, speaking and listening, and pronunciation. (Reading and writing and speaking and listening are compound items, so the commas fall between the items, not inside the pairs.)
AvoidThe keys, wallet, and phone, were on the counter. (A comma after the final item separates the subject from its verb.)
AvoidPlease send the signed agreement, and the deposit. (Two items joined by a conjunction form a pair, not a list, so they take no comma.)