I.e vs. E.g.

Riley Thompson Manning

Ready to learn a little Latin? The abbreviations i.e. and e.g. are two of the most mistakenly-used words in the writing world. Even highly-educated professionals mix up i.e. and e.g. in their technical writing all the time. (I wonder what “no brainer” is in Latin?)

The short version

I.e. stands for “id est,” which means “in other words.”

Use i.e. when taking a complex idea and restating it to make it easier to understand. It can also be used to signify a clarification or making something more specific.

E.g. stands for “exempli gratia,” which means “for example.”

Use e.g. to follow an idea with scenarios that illustrate that idea. It is a presentation of that idea in action, not a clarification of it, as with i.e.

As usual, there is a little more than meets the eye with these two abbreviations, so let’s take a closer look.

When to use I.e.

Have you ever had someone explain something in very technical terminology, terminology that went over your head entirely? Perhaps you responded by saying, “In English, please?” That’s how you can remember the meaning of i.e. This abbreviation says, “Let me make it clearer for you.”

Grammatically, i.e. comes with a few rules to know.

When writing i.e. in a sentence, set it off with commas before and after the abbreviation. There’s a lot of debate over whether to use one comma or two, but most stylebooks advise using both.

It’s inadvisable to begin a sentence with i.e. If you find yourself in that position, use a phrase like, “That is to say,” instead.

Usually i.e. and the clarification that follows ends a sentence. However, if you find yourself returning to the original sentence after the clarification, you may set the i.e. statement off with dashes or put the statement in parentheses. In this case, you still need the comma after the abbreviation.

Here are some examples:

  • After studying chemical engineering, she took a job with a firm that creates polymers (i.e., versatile forms of plastic) that are used in vehicle paint.
  • Olympic lifting exercises primarily emphasize your gluteal maximus and erector spinae muscle groups, i.e., your posterior chain.
  • At the Cow Bone steakhouse, parties of six or more are automatically charged gratuity--i.e., a 20 percent tip--which is added to the final ticket.

In sentence 1, the i.e. statement is telling you what polymers are and isn’t adding any information or examples. In sentence 2, it’s telling you what the muscle groups are collectively called. In sentence 3, is giving more detail to the existing information without adding information.

When to use E.g.

When pronouncing the word “example” aloud, you might use a “g” sound in place of the “x.” Many people do. This can help you remember the abbreviation’s meaning. The e.g. abbreviation adds information, whereas i.e. restates information.

It’s inadvisable to begin a sentence with e.g. If you find yourself in that position, simply spell out, “For example.”

The grammar rules regarding commas, etc., are the same as with i.e., which are listed in the section above. That brings up one other common mistake: lots of writers incorrectly end their e.g. idea with “etc.” Etc. should never conclude an e.g. idea.

Here are some examples:

  • There are many monuments in Washington D.C. I’d like to visit, e.g., the Lincoln Memorial and the Washington Monument.
  • Regina’s headaches subsided as soon as she cut foods with gluten (e.g., pasta, rolls, cookies) out of her diet.
  • This part of the country used to be populated by Native American tribes—e.g., the Choctaw, Chickasaw, and others—and we still celebrate that rich history today.

In sentence 1, the Lincoln Memorial and Washington Monument are examples of monuments the speaker would like to visit, but it is not a complete list. In sentence 2, the e.g. statement isn’t telling you what gluten is, but rather giving examples of food Regina has stopped eating. In sentence 3, again, the e.g. statement is not giving a complete list.

Pop Quiz

Use the sentences below to check your understanding of i.e. and e.g.

  1. The mitochondria (i.e., e.g.), the powerhouse of the cell) generate energy within the cell.
  2. Kevin’s father is the architect behind many sports arenas, (i.e., e.g.), the FedEx Forum in Memphis and the Mercedes-Benz Superdome in New Orleans.
  3. Henry James novel, “The Turn of the Screw,” ends by abandoning the reader in a state of liminality, disrupting the diegetic flow, and leaving the reader thoroughly disconcerted, (i.e., e.g.), you don’t really know what happens at the end, and it creeps you out.
  4. Your credit score is determined by numerous credit factors, (i.e., e.g.), your history of making credit card payments on time and your debt utilization ratio.
  5. Did you see the new stadium Kevin’s father built, (i.e., e.g.), the FedEx Forum?
  6. Many biblical stories, (i.e., e.g.), Jonah getting trapped in the whale, Joseph and his colorful coat, and the mighty Samson, have a deeper meaning I didn’t understand until I became an adult.
  7. I’m going to douse this soup with my favorite topping, (i.e., e.g.), Sriracha sauce.
  8. Each of your cells contains smaller organelles that perform specific functions—(i.e., e.g.), mitochondria, nucleus, and ribosomes—to maintain the health of the cell.
  9. Artists like Michelangelo, Filippo Brunelleschi, and Giorgio Vasari, (i.e., e.g.), Renaissance period painters, thrived from the year 1300 to around 1700.
  10. This winter, the Salvation Army needs cold weather clothing, (i.e., e.g.), jackets, hats, and gloves.

Answers: 1. i.e., 2. e.g., 3. i.e., 4. e.g., 5. i.e., 6. e.g., 7. i.e., 8. e.g., 9 i.e., 10. e.g.