Comma After i.e. and e.g.

By Maeve Maddox

A reader wants to know if the abbreviations i.e. and e.g. should be followed by a comma.

i.e.: from the Latin phrase id est, “that is.” Used in English to restate a previous word or expression: “He really enjoys a good bildungsroman, i.e., coming-of-age novel.”

e.g.: from the Latin phrase exempli gratia, “for the sake of the example.” In English, it means “for example” and is used to introduce one or more examples: “I like animals, e.g. dogs, cats, and horses.”

The two terms are frequently mixed up. If you have trouble remembering which means “in other words” and which means “for example,” you can use a mnemonic to keep them apart, or you can avoid using them altogether.

A simple mnemonic that helps many writers is the fact that the word example begins with the letter e. E.g., therefore, is the one that means “for example.”

On the other hand, instead of e.g., you can write “for example,” and for i.e., you can write “namely” or “in other words.”

Style guides do not agree on whether or not a comma should follow both these abbreviations. They do all agree that a comma precedes i.e. when the i.e. phrase occurs in a running text (i.e., not enclosed in parenthesis).

The consensus seems to be in favor of the comma in American usage; against it in British usage.

The Penguin Writer’s Manual (British) shows both i.e. and e.g. without a following comma.

Fowler, in his venerable Modern English Usage, opines that

“whether a comma follows [e.g.] or not is indifferent, or rather is decided by the punctuation-pitch of the writer of the passage.

He says nothing of i.e.

The Chicago Manual of Style states that i.e. and e.g. should be “confined to parentheses and notes and followed by a comma.”

The AP Stylebook, whose “punctuation-pitch” leans generally to the side of “the fewer commas the better,” is pro-comma when it comes to i.e. and e.g. According to AP, both abbreviations are “always followed by a comma.”

As with so many matters of punctuation, the writer’s best practice is to choose a style reference and follow its recommendations.

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5 Responses to “Comma After i.e. and e.g.”

  • Elysia

    Thanks for this! I had not been aware it was even an option not to use a comma. Perhaps I’ve overedited on this point on occasion. :-O

  • Virginia Llorca

    I always use a colon as you did in your initial examples, e.g.: just like this. Don’t recall being corrected. Will check Chicago Manual.

  • Shing

    I like animals, i.e. dogs.
    I like animals, i.e., dogs.
    I like animals. I.e. Dogs. I also like plants. I.e. Roses. <- Best
    i.e. should just be avoided.

    I like animals, e.g. dogs, cats, and horses.
    I like animals, e.g., dogs, cats, and horses.
    I like animals. E.g. Cats and dogs. I like deserts. E.g. Cakes and cookies. <– Clearest if in-line.

  • Stephanie

    @Shing, your use of [i.e.] is incorrect in the examples you gave. The term means “in other words” and not “for example.”

    I like sports, .e.g., baseball, basketball, and tennis. The phrase after [e.g.] lists examples of the sports I like but does not define the word “sports” or the phrase “I like sports.”

    I like baseball, i.e., a popular sport in the U.S. involving batting a ball and running bases. –> The phrase after [i.e.] defines the noun it follows.

    The example in the article was: “He really enjoys a good bildungsroman, i.e., coming-of-age novel.”

  • Shameem

    @Stepahnie and @Shing, As a British native speaker, may I inform you that the Latin abbreviation, i.e., does not mean “in other words” or “for example.” It means: “that is (to say).” The Latin abbreviation, e.g., means “for example.” Furthermore, viz., means “namely.” I hope that helps 😉

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