Punctuating a Series

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In order to avoid confusion, it is necessary to separate items in a series with punctuation.

Read the following:

At the store, I bought red pepper salsa wheat tortillas and cheese.

What was bought? Red pepper and salsa, or red pepper salsa? Wheat and tortillas or wheat tortillas? Punctuation marks could eliminate confusion.

Simple Series

When writing a series of three or more items, separate each item with punctuation—usually commas. Generally, a conjunction (and, or) will follow the last comma in the list.

Example:     At the store I bought red pepper, salsa, wheat tortillas, and cheese.

Note: Although the serial or Oxford comma (the comma preceding and in a series) is not used in journalistic and informal writing, it is still required in formal and academic writing.

Interestingly, the use of an ampersand (&) instead of and in a series requires no serial comma.

Example:     I received counsel from Brooks, McCarthy, Dunn & Derringer, attorneys at law.

Commas are not needed in a series whose elements are all joined by conjunctions.

Examples:   I bought salsa and tortillas.
Was it wheat tortillas or flour tortillas or corn tortillas?

Etc. and so forth are both preceded and followed by a comma.

Examples:   I bought salsa, tortillas, cheese, etc., at the store.
The cashier asked me if I wanted to pay by check, cash, and so forth, when I reached the register.

Note: For more information on comma usage see the handout Commas.

Complex Series

When a sentence contains a series of items that have internal punctuation or that are very long and complex, separate the items in the series with semicolons.

Example:     The authors of the textbook include Dr. Susan Lyons, Ph.D; Marcia Shelagan, a noted computer theorist; and Richard Everly, a systems specialist at IBM.
Example:     Ajax Meats has three major divisions: the East, which specializes in quality control; the West, which specializes in research and development; and the North, which specializes in keeping dead rats out of the meat.

Note: For more information on semicolons see the handout The Colon, Hyphen, Dash & Semicolon.

Introducing a Series

Colons

When using a colon to introduce a series, the colon must follow a complete sentence and cannot immediately follow the main verb of the clause.

Incorrect:    His list of office supplies contains: ceramic pots, a pair of white gloves, a wooden stool, and twenty-five boxes of paper clips.
Correct:       His list of office supplies contained unusual items: ceramic pots, a pair of white gloves, a wooden stool, and twenty-five boxes of paper clips.

Note: For more information on colons see the handouts The Colon, Hyphen, Dash & Semicolon and Comma Splices and Fused Sentences.

Serial Phrases

Serial phrases (the following, as follows) can introduce a series with a colon as long as they are part of a complete sentence.

Example:     Weight reduction includes the following: proper diet, aerobic exercise, and flexibility exercises.

Some serial phrases like such as and includes are not followed by a colon when they are not part of a complete sentence.

Incorrect:    The old pool was filled with junk, such as: tires, leaves, and broken pieces of wood.
Correct:      The old pool was filled with junk, such as tires, leaves, and broken pieces of wood.
Or:             The pool was filled with junk, including tires, leaves, and broken pieces of wood.
Or even:     The old pool was filled with junk: tires, leaves, and broken pieces of wood.

i.e., e.g., and Namely

Introducing a series with i.e. (id est—that is), e.g. (exempli gratia—for example), or namely requires the use of a comma immediately following the phrase.

Examples: He had many luxuries (e.g.,  a Ferrari, a pet monkey, a ten-foot-deep bathtub, and seven swans a-swimming).
Only the most qualified employees worked on the project, namely, Burnett, Johnson, Reeves, and Nowacki.

James Gunter, summer 2005