How to Use i.e. in a Sentence

Deciding When to Use “i.e.”

Use "i.e." to say “that is” or “in other words.” Use the abbreviation "i.e.” when you want to add on to the first part of a sentence and give the reader more information. The information should explain the first part of the sentence in more detail so the reader understands it better. For example, you may write, “I am a vegan, i.e., I do not eat any animal-based products” or “He works the morning shift, i.e., from 6 am to 1 pm.”

Do not use "i.e." to say “for example” or “such as.” The abbreviation “i.e.” should not be used if you want to provide an example or illustration of what you mean for readers. If this is the case, you should use “e.g.” instead of “i.e.” “E.g.” stands for the Latin phrase “for the sake of example.” For example, you would write, “I do not like eating raw fish, i.e., sushi.” and “I don't like Japanese food, e.g., sushi or ramen." Or you may write, “She likes poetry about love, i.e., poems that explore matters of the heart” and “She likes poetry about love, e.g., poems by the New Romantics.”

Use this abbreviation in informal documents or as shorthand. You may put “i.e.” in a sentence if you are writing an email or a letter to a friend, an informal piece of writing for a class, or a quick business note. If you are writing a formal business document or an academic paper, consider using “that is” or “in other words” instead. In some cases, using “i.e.” in a news article, an essay, or an academic paper may be okay. Double check with your instructor to make sure it is appropriate for you to use this abbreviation in a paper or essay.

Putting “i.e.” in a Sentence

Lowercase it and use periods. The abbreviation “i.e.” should always appear with a lowercase “i” and a lowercase “e” in a sentence, with a period between both letters.

Do not italicize or bold it. The abbreviation "i.e." does not need to be formatted differently than the rest of the document or paper. Leave it in regular case, with no italicizing or bolding.

Place a comma before and after “i.e.” This will help the abbreviation stand out and let the reader know you are providing additional information after “i.e.” For example, you may write, “He prefers native plants in the garden, i.e., plants that naturally grow in the area” or “I have a soft spot for holiday music, i.e., songs that are about Christmas or Halloween.”

Put "i.e." in the middle of a sentence, never at the beginning or end. The abbreviation “i.e.” should always appear after the first section of the sentence, in the middle, so it is grammatically correct. For example, the sentence, “I.e. he likes super heroes” or the sentence, “He likes super heroes, i.e.” are incorrect. The correct sentence would be, “He likes super heroes, i.e., social misfits who save the world.”