Grammarama

E.g. vs. I.e.

I.e. is an abbreviation for id est, which is Latin for that is. E.g. is an abbreviation for exempli gratia, which is Latin for for the sake of example. Even though i.e. stands for that is, you can’t use it to replace those words in every situation. For example, Mercury is the planet that is closest to the Sun can’t simply be rewritten as Mercury is the planet i.e. closest to the Sun. It would be more appropriate to think of i.e. as standing for that is to say.

I.e. and e.g. are usually written parenthetically, and they are both used to expound in some way upon the word or phrase that precedes the parentheses; however, they each accomplish this in their own distinct way. I.e. is a further or clearer description, whereas e.g. lists one or more examples to represent the preceding word or phrase.

Think of i.e. as standing for “in essence,” for it clarifies and gets to the essence, and think of e.g. as standing for “eggsample(s).” Horrible pun, I know, but that should make it all the harder to forget.


Examples:

Tom says his fourth grade teacher (i.e., Ms. Jones) was the best he ever had.
There are countless breeds of dog (e.g., German Shepherd, Golden Retriever, Great Dane).
Leonardo Da Vinci (i.e., painter of the Mona Lisa) was quite possibly the most famous figure of the Renaissance.
Most of the asteroids in our Solar System (e.g., Ceres and Vesta) are found in the Asteroid Belt, which lies between Mars and Jupiter.
No one knows, or will ever know for a fact, who fired the bullet that killed Manfred von Richthofen (i.e., The Red Baron).
Supergiant stars (e.g., Antares, Betelgeuse, and Rigel) are farther away than many others we can see, but their tremendous size makes them some of the most luminous objects in the nighttime sky.

If it’s at all possible to avoid using i.e. or e.g. at all—and it usually is—then perhaps you should do that. Your goal when writing is to express ideas as clearly as possible for the reader, and judging by the fact that I’m devoting an entry to this subject, not everybody understands the difference between the two abbreviations. Here are alternatives to the examples above that don’t include i.e. or e.g.:

Tom says his fourth grade teacher, Ms. Jones, was the best he ever had.
There are countless breeds of dog, including German Shepherd, Golden Retriever, and Great Dane.
Leonardo Da Vinci, who painted the Mona Lisa, was quite possibly the most famous figure of the Renaissance.
Most of the asteroids in our Solar System—Ceres and Vesta, for example—are found in the Asteroid Belt, which lies between Mars and Jupiter.
No one knows, or will ever know for a fact, who fired the bullet that killed Manfred von Richthofen, better known as The Red Baron.
Supergiant stars such as Antares, Betelgeuse, and Rigel are farther away than many others we can see, but their tremendous size makes them some of the most luminous objects in the nighttime sky.