Understanding how to use “i.e.” in sentences is crucial for clear communication. “i.e.” stands for “id est,” a Latin phrase meaning “that is” or “in other words.” It’s used to clarify or specify information. The question of whether a comma should follow “i.e.” is common.
This guide will provide rules and examples to help you use “i.e.” correctly in various scenarios.
Rules for Using Commas with “i.e.”
Rule 1: After “i.e.”
Traditionally, a comma is used after “i.e.” to introduce the explanation or clarification that follows.
Correct Examples:
- “You’ll need to bring stationary, i.e., pens, pencils, and paper.”
- “He prefers to eat late, i.e., after 9 PM.”
Incorrect Examples:
- “You’ll need to bring stationary, i.e. pens, pencils, and paper.”
- “He prefers to eat late, i.e. after 9 PM.”
Rule 2: Before “i.e.”
A comma is also typically used before “i.e.” when it introduces a clarification within a sentence.
Correct Examples:
- “She has one hobby, i.e., painting, that takes up most of her free time.”
- “We visited the capital, i.e., Washington, D.C., last summer.”
Incorrect Examples:
- “She has one hobby i.e., painting, that takes up most of her free time.”
- “We visited the capital i.e., Washington, D.C., last summer.”
Rule 3: Beginning Sentences
When “i.e.” starts a sentence, which is less common, it should be followed by a comma.
Correct Examples:
- “I.e., the study focuses on environmental impacts.”
- “I.e., they were all in agreement with the plan.”
Incorrect Examples:
- “I.e. the study focuses on environmental impacts.”
- “I.e. they were all in agreement with the plan.”
Rule 4: In Parentheses
When “i.e.” is used within parentheses, it is followed by a comma.
Correct Examples:
- “He’s an expert in renewable energy sources (i.e., wind and solar power).”
- “She can play several instruments (i.e., piano, guitar, and drums).”
Incorrect Examples:
- “He’s an expert in renewable energy sources (i.e. wind and solar power).”
- “She can play several instruments (i.e. piano, guitar, and drums).”
Rule 5: In a Series
When used in a series to clarify the last item, “i.e.” is preceded by a comma and followed by another comma.
Correct Examples:
- “She’s lived in many cities, including New York, Los Angeles, and, i.e., the most recent, San Francisco.”
- “He’s skilled in many programming languages, such as Java, Python, and, i.e., his favorite, JavaScript.”
Incorrect Examples:
- “She’s lived in many cities, including New York, Los Angeles, and i.e. the most recent, San Francisco.”
- “He’s skilled in many programming languages, such as Java, Python, and i.e. his favorite, JavaScript.”
Additional Rules and Examples
While the above rules cover the most common scenarios, the key takeaway is that “i.e.” typically requires a comma both before and after its use. This punctuation not only adheres to traditional grammar rules but also improves readability and comprehension, ensuring that the clarification or specification it introduces is clearly separated from the rest of the sentence.
Remember, using “i.e.” correctly enhances the precision and clarity of your writing, allowing you to specify information succinctly and effectively.
Dariel Campbell is currently an English instructor at a university. She has experience in teaching and assessing English tests including TOEFL, IELTS, BULATS, FCE, CAE, and PTEG. With over a decade of teaching expertise, Dariel Campbell utilizes his knowledge to develop English lessons for her audience on English Overview.
