The Easy Explanation
“e.g.” is an abbreviation that means for example: The chef added many flavors (e.g., cilantro, garlic, and cumin) to the stew.
“i.e.” is an abbreviation that means that is to say: The culprit (i.e., my brother) returned the stolen diary.
When to Use e.g. vs. i.e.
The abbreviation “e.g.” is shortened from the Latin term exempli gratia, which translates to for example—and that is exactly what “e.g” does: It introduces examples that clarify or focus a more broad point:
He had said he would never own a foreign-made car (e.g., a Kia or a Toyota), but he seemed to have no trouble accepting the gift of a Mercedes.
The abbreviation “i.e.” is shortened from the Latin term id est, which translates to that is (as in in other words). It also serves to introduce a kind of clarification—a more specific retelling of a point made within a sentence:
The world’s largest democracy (i.e., India) held crucial elections last year.
When you use “i.e.,” you are telling the reader that this is the only possible retelling: India is the world’s largest democracy, and no other answer is possible.
While the two abbreviations are used differently, they are formatted similarly. Both letters are lowercase and nearly always followed by periods. They are most often offset within parentheses (or occasionally within em-dashes or commas). In American English, the abbreviations are typically followed by a comma; in British English, there typically is no comma.
The two countries (i.e., the USA and England) each have different grammar rules. (offset within parentheses and using the American style of a comma after)
The two countries—i.e. the USA and England—each have different grammar rules. (offset within em-dashes and using the British style without a comma)
Examples of e.g. vs. i.e.
- Caffeinated beverages (e.g., coffee, soda pop, and tea) are necessities in my life. (used to introduce examples of which there are a few)
- Unfortunately, my preferred caffeinated beverage of choice (i.e., Diet Coke) was sold out. (used to offer a more specific retelling—Diet Coke is the only drink of choice)
- The family pet (i.e., the pet rock they brought home from a trip to Hawaii) is not terribly dynamic. (the only pet this family has is a pet rock: family pet=pet rock)
- The family pet (e.g., a dog or a cat) is often a special part of the family unit. (many types of pets are possible)
How to Remember the Difference
The most straightforward way to test is to replace the abbreviations with their translations:
John put on his nicest sweater (i.e., the one without any holes) for the first date.
With these and see what makes sense:
John put on his nicest sweater ([FOR EXAMPLE], the one without any holes) for the first date.
John put on his nicest sweater ([THAT IS TO SAY], the one without any holes) for the first date.
There are also some memory tricks to help remember which abbreviation is which. One is to think about “e.g.” standing for examples given. Another is to think about “e.g.” meaning “for e.g.-xample” (“egg-xample”). For i.e., meanwhile, you can remember that it means in essence.
Theory Into Practice: Which Is Which?
Is the underlined word correct? See if you can tell.
- The cake recipe is long, but at least the ingredients (e.g., flour, eggs, and sugar) are cheap.
Right: There are many ingredients; flour, eggs, and sugar are just a few examples of those ingredients.
- Board games (i.e., Monopoly) became increasingly popular throughout the twentieth century.
Wrong: This sentence implies that Monopoly is the only board game when there are—of course—many board games.