The Latin abbreviations e.g. and i.e. are used extensively in English. Not everyone, however, is aware of the difference in their usage. Some people use them interchangeably. Others even invert their meaning. If you are not completely sure when to use each of those abbreviations, keep reading!
e.g. stands for the Latin phrase “exempli gratia,” which means “for the sake of example.” You should use it when presenting examples or more possibilities for the term in question. An easy way to remember this is to associate e.g. with “example given.”
I like citrus fruits (e.g., oranges and lemons)
i.e. Stands for the Latin phrase “id est,” which means “that is.” You should use it when explaining or rephrasing a sentence. Usually it has the same meaning as “in other words.”
I like all fruits (i.e., I eat pretty much anything)
You can use the e.g. and i.e. abbreviations both inside and outside the parenthesis. If you are writing in a formal style, however, they must go inside the parenthesis
They appear in lower case letters even if at the beginning of the sentence
Always separate the letters with a period, and follow the abbreviation with a comma