I.e. and e.g. are abbreviations of the Latin phrases id est andexempli gratia. In English, we use e.g. to meanfor example or for instance and i.e. to meanin essence, namely or in other words. The abbreviations e.g. and i.e. are commonly used in writing, mainly academic writing, but also in informal writing and sometimes in everyday speech.
Because the abbreviations e.g. and i.e. look similar and have similar meanings, they can sometimes be confused. Actually, as a likely result of the confusion, the Merriam-Webster Dictionary cites e.g. and i.e. as the most commonly looked up abbreviations in English.
Let’s look at some examples of the two commonly used abbreviations:
E.g. means for example
I.e. means in essence or in other words or namely
As mentioned, the meanings of i.e. and e.g. are quite similar, so you can understand why they are often confused in writing. E.g. is used to start a clause when giving an example. I.e. is used to start a clause when giving an explanation.
To demonstrate, let’s look again at two of the examples given above that looked quite similar:
E.g. is correct here, because there are five Nordic countries, and we are using e.g. to give an example of some of them.
I.e. is correct here, because there are only two Iberian countries, Spain and Portugal, and we are using i.e. to explain that.
Here is another example:
We are speaking about Republican presidents in a general fashion, using e.g. to introduce an example of two of them, Abraham Lincoln and Ronald Reagan.
There have only been two Republican presidents in the 21st Century, so we use i.e. to introduce an explanation that they are Donald Trump and George Bush.
The trick to remembering the difference between i.e. and e.g. is to focus of the meaning of the two abbreviations.
I.e. roughly means namely or in other words, but another way of saying it is the phrase in essence. As you can see, the first letters of each word in the phrase in essence are i ande, thus we can easily use that trick to remember the meaning of i.e.
We associate e.g. with giving examples, so some people try to think of the e in e.g. as the first letter of example. Others create phrases like example given, focusing on the first two letters, e and g, to remember the meaning ofe.g. Another way to remember that e.g. means for example is to think that e.g. sounds like the egg in example.
We have looked at i.e. to an extent, but what does it really mean? It is short for the Latin phrase id est, which literally translates as that is. However, the meaning in English is a bit more specific, and it is used to mean things likenamely, in essence, essentially, in other words or that is to say. Normally, these phrases are used to introduce a clause stating that one thing is effectively the same as another. In a way, i.e. introduces a clarification and says: this is another way of understanding this previous piece of information.
Let’s look at another example:
Joel and Ethan Cohen are famous movie makers, but they are also known collectively as the Cohen Brothers. We use i.e. here to introduce the clause that states another way of recognizing Joel and Ethan Cohen is by the term the Cohen Brothers.
The usage of e.g. is perhaps a bit easier to understand than i.e. as it clearly means for example. The Latin term from which we get the abbreviation, exempli gratia, can be translated as for example or for instance. When we use phrases like for instance or for example, they will normally introduce one or more things from a collection to state that they are examples of what was previously said.
Let’s look at another example:
As you might expect, there are many names that could be considered biblical. By using e.g., we are introducing a clause to say that John and David are two examples of those names. If we used i.e. in place of e.g. here the sentence would not be factual, because it would suggest that there are only two biblical names, John and David.
Understanding the difference between i.e. and e.g. can be tricky but learning how to use them correctly in writing can be even more difficult. The reason for this is that there is some disagreement in the punctuation used for the abbreviations and even how they are spelled. For example, a minority of style guides will ask that you spell e.g. and i.e. as eg and ie. Most prestigious style guides, however, prefer to use the periods to split the letters.
You may also have noticed the use of the comma after i.e. and e.g. when using them in a sentence. Again, this is a subject that grammarians will debate intensely. However, the short answer is that the use of the comma after e.g. and i.e. is more prevalent in American English (as opposed to British English).
Let’s be honest about it, all that punctuation looks a bit weird. So, how do we know it’s correct? Well, let’s take the meanings of e.g. and i.e. to be for example and in other words and use them in some examples:
If we directly replace for example with e.g. here, you can see why we still need the comma.
And, an example using in other words:
If we directly replace in other words with i.e. here, you can see why we still need the comma.
Have a look at these original examples of how to use i.e. and e.g. in writing: