The Difference between ‘I.e.’ and ‘E.g.’
Since not everyone knows what the abbreviations ‘i.e.’ and ‘e.g.’ stand for, they are often confused in writing. Using either incorrectly can look bad, though, so it’s a good idea to make sure that you understand the meaning and usage of both.
‘I.e.’ is an abbreviation of the Latin words ‘id est’, meaning ‘that is’. Think of it as standing for ‘that is to say’ or ‘in other words’. It is typically used to introduce a clarification or explanation. For example:
The holiday package is all inclusive: i.e. meals, drinks, and activities are included in the overall price.
‘I.e.’ can also be used if introducing a complete list of the items included in a category:
In The Three Musketeers, d’Artagnan befriends the titular trio (i.e. Athos, Porthos, and Aramis).
In this example, using ‘i.e.’ indicates that Athos, Porthos and Aramis are the three musketeers mentioned earlier in the sentence.
‘E.g.’ is an abbreviation of the Latin term ‘exempli gratia’, literally meaning ‘for the sake of example’. As this might suggest, it is used to introduce an example related to the preceding statement, such as in the following:
In some situations, fear is a rational response: e.g. when you notice a large spider crawling up your leg!
It can also be used to introduce a list which illustrates a statement. Unlike with ‘i.e.’, lists which follow ‘e.g.’ are not exhaustive, but rather provide a small selection of examples:
Australia is home to some of the most venomous spiders in the world: e.g. the redback, the mouse spider, the fiddleback, and the Sydney funnel-web.
Technically, a list which follows ‘e.g.’ should not be finished with ‘etc.’, because ‘e.g.’ implies a non-exhaustive list and ‘etc.’ means ‘and so forth’. Consequently, using both is redundant.
In Australian English, ‘i.e.’ and ‘e.g.’ are not usually followed by a comma, but many American style guides recommend that they should be.
In formal writing, it’s usually better to use ‘i.e.’ and ‘e.g.’ either after a colon or within parentheses. If you want to include them in the main body of your work, you might want to use ‘for example’ or ‘that is’ instead, unless your style guide suggests otherwise.
In other contexts, it should be fine to use these terms in the main text of your work, but they need to be preceded by a comma, like this:
There are many fashion houses based in Paris, e.g. Dior, Chanel, and Louis Vuitton.
‘i.e.’ or ‘e.g.’?
Remember that ‘i.e.’ comes before a definition or explanation of a statement, while ‘e.g.’ comes before an example which illustrates the previous statement.