What does i.e. mean?
I.e. stands for id est, Latin for that is. It is used to clarify or restate something more precisely, as in the capital of France, i.e., Paris.
Use i.e. when you want to explain exactly what you mean or give a specific clarification. For example: She studied the largest planet, i.e., Jupiter. Here, i.e. introduces the single thing that fits the description. A helpful way to remember it is in other words or in essence.
In American English, i.e. is usually written with periods and followed by a comma. In British English, the comma is often left out. Like other Latin abbreviations, it is common in academic and technical writing, but in everyday writing, phrases like that is or in other words can be clearer.
Common mix-up
People often confuse i.e. with e.g., which means for example. Use i.e. to clarify, and e.g. to give examples. If you could replace it with that is, use i.e. If you could replace it with for example, use e.g.
Did You Know?
Both i.e. and e.g. are usually written in lowercase and not italicized in modern style guides.