The abbreviation i.e. carries the definition for the Latin phrase id est, which translates to that is. Writers commonly use i.e. to avoid writing out “in other words,” “in essence,” “what that means is,” or “that is to say.”
The Latin expression id est is not common in modern English language, but that’s not to say we don’t hear people say, “i.e.” before listing several examples of the related subject they’re discussing. But what does i.e. mean and why is it useful for clarifying ideas? The answers lie in how the English dictionary adopted Latin phrases to convey universal ideas.
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Latin is one of the oldest languages used throughout several regions of the world and is first documented in Rome, Italy around the time of 753 BC. Latin has had a profound influence over the way people communicate around the world, and especially through Romance languages and European history.
It’s no wonder, then, how often we use Latin phrases and abbreviations within the English language every day. Latin is still commonly used in law theory, scientific and medical terminology, and within classical studies. The use of Latin abbreviations, such as i.e., is quaint in the way of how we connect modern communication to some of the earliest forms of Western European linguistics.
What is i.e. and what does i.e. stand for?
The Latin abbreviation i.e. stands for id est and translates to “that is” in English. It is common to see academic writers use i.e. in place of writing out “in other words,” “that is to say,” what that means is.” The primary purpose of using i.e. is to introduce examples and clarify main points.
When to use i.e.
The proper way to use i.e. in writing is to use it as a tool. Because i.e. allows one to avoid writing out “in other words,” or “in essence,” it’s important to remember the context of where it’s used. If you’re looking to narrow down your point to specific ideas, then i.e. is an appropriate abbreviation to use before introducing those terms.
Here is an example of where i.e. is used correctly:
“We have read profound writings by French authors (i.e., Hélène Cixous and Michel Foucault) who changed the way postmodern literature is critiqued.”
In this example, i.e. is correctly used because it allowed the author to make a point and narrow their position further. The author could have omitted the names of Cixous and Foucault, but the reader wouldn’t know who they’re referencing specifically.
The abbreviation and notion of i.e. are also common in speech when one says, “in essence.” More common in philosophical texts or literary critiques, i.e. is used to paraphrase an idea more directly, or to introduce a different way of saying the same thing. For example,
“Foucault reintroduced the Panopticon as a method of authoritarian control over society, which, in essence, compares all forms of societal regulations to a prison system model.”
Using i.e., or in other words, is like placing a big equal sign toward the end of a sentence, or like using the term “a.k.a.,” for “as known as.” The abbreviation i.e. is used to clarify promptly and nothing more.
Using i.e. for style guides
There are exceptions to using i.e. in academic or formal writing, and that is when using APA, MLA, or Chicago style guides. Each style guide advises against using Latin words or abbreviations within the writing body itself, although i.e. is permitted within parentheses.
Less-common Latin abbreviations are only accepted when they are used within tables, footnotes, and endnotes. Court documents often use Latin abbreviations or words for legal jargon, and this remains to be a common exception to style guide rules.
The ban on using archaic Latin abbreviations exists because abbreviations are initially applied to provide more clarity to readers. If modern audiences do not understand what the abbreviation is conveying, the writer is making their message less transparent and more complex.
How to use i.e.
As with all Latin terms, the abbreviation of i.e. and its untranslated phrase id est are always lowercase within a sentence. When using i.e. in a sentence, be sure to always use periods in between i and e, and a period with a comma directly after the e. For example,
It’s nearly the holiday season (i.e., October through December) and I couldn’t be more excited!
In addition, Latin expressions are usually italicized similarly to that of a diacritic symbol, such as an accent symbol, to indicate a phrases’ foreign origin or pronunciation. Unlike full Latin phrases, Latin abbreviations are not italicized. Latin expressions that are listed within Merriam-Webster’s Dictionary, however, are not italicized because they are considered apart of the standard English language. Examples of such include,
Is i.e. the same as e.g.?
While both abbreviations are Latin and have similar meanings, i.e. is not the same as e.g. The abbreviation e.g. stands for exempli gratia, which translates to for the sake of example. We use the definition of e.g. every day without knowing it, such as when stating “like,” “for example,” “such as,” or using punctuation marks such as the em-dash or colon.
Unlike i.e., which is used to clarify a point, the abbreviation e.g. is used to provide a broader context of one’s subject matter. The abbreviation e.g. is primarily used to give a few examples within a sentence, though, and isn’t meant to take the place of a colon exclusively.
The abbreviation e.g. abides by the same style guide rules and punctuation as i.e., although e.g. is used very differently. The most significant difference between the two is that e.g. is used to provide similar examples to the subject, while i.e. is used to reference a specific idea.
How to use i.e. versus e.g.
Let’s take a look at a few examples of the differences between using i.e. and e.g. appropriately:
Incorrect: Modern geologists expect U.S. states located on the Cascadia subduction zone (i.e., California) to experience a catastrophic earthquake.
Correct: Modern geologists expect U.S. states located on the Cascadia subduction zone (e.g., California) to experience a catastrophic earthquake.
The first example given is incorrect because California is not the only U.S. state located on the Cascadia fault. California is one of the three U.S. states situated on the Cascadia fault, though, and so the use of e.g. in the second sentence is correct.
Choose which sentences are using the correct form of i.e.:
It’s nearly December (i.e., the month of Christmas).
All wedding attendees are expected to wear formal attire (i.e., gowns) and to arrive on time.
Students were caught using internet search engines (i.e., Google) to cheat on their exams.
We have a resource for English translations (i.e., a thesaurus) and yet my students failed their Latin word test.
I don’t enjoy eating citrus fruits (i.e., lemons).
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Alanna Madden is an online content editor and freelance writer based out of Portland and Eugene, Oregon. She has over three years of professional experience involving arts, culture, and news editing, and currently specializes in data reporting on US higher education. Alanna graduated from Portland State University with a Bachelor of Science in English with a writing minor. In addition to literary studies, she spent several years studying molecular biology and volunteering as a research assistant at Oregon Heath and Sciences University. Outside of work, Alanna enjoys reading and writing about literary criticism and participates in local writing groups. I can be found on Linkedin .