While i.e. and e.g. may appear to quite similar, they are actually quite different. And it's more than just their Latin roots! Below is a short summary to ensure you don't get caught out when writing content.
e.g. = Example gratia = For example Used to provide an example of what was just mentioned. "You can buy eggs in lots of different sizes, e.g. a half dozen."
i.e. = Id est = That is Used to clarify what was just mentioned. "The discount is available during weekday breakfast, i.e. between 6am and 10am, Monday to Friday."
How to know when to use i.e. vs e.g.?
If providing an example always use e.g., and if providing more detail or clarifying a statement us i.e..
Unsure? When writing your sentence simply replace the abbreviation with "for example" or "that is". Whatever sounds right is usually what you should be using.
And - this might sound crazy - if you're really not sure, say your sentence out loud! Trust me it works every time. Reading your sentence out loud can also help you identify sentence structure issues in your copy.