Grammar (All About) Parentheses |
The Blue Book of Grammar and Punctuation

(All About) Parentheses

The singular form is parenthesis, but the plural parentheses is the word you’re more likely to see. Both words have a wide range of related meanings, and what some people identify as a parenthesis, others call parentheses.

So let’s keep it simple. For our purposes, a parenthesis is one of a pair of curved marks that look like this: ( ), and parentheses are both marks.

A symbol, number, word, phrase, or clause that is in parentheses explains, supplements, or comments on something in the sentence. Material in parentheses can be removed from a sentence without changing that sentence’s overall meaning or grammatical integrity.

Note the use of is in this sentence: My friend (and her brother) is coming today. The subject is My friend. Despite appearances, parentheses are never part of the subject. Remove them and we’d have two subjects, My friend and her brother, which would require the verb are coming. The use of parentheses is a clue that the writer was more concerned about the friend than about the brother.

Parentheses, long dashes, and commas are the three punctuation marks that indicate an interruption in the flow of a sentence. (Some might add semicolons, which can turn two simple sentences into a single, more complex sentence: Their eyes met; she smiled.)

Commas, the least intrusive of the three, signal the presence of relevant but nonessential data. Long dashes either expand upon the main point or take a slight detour from it. Parentheses by their very appearance let the reader know that the information fenced off by those vertical curves is a departure from the rest of the sentence. To illustrate:

Blaine, who was born in 1797 and died in 1860, did not live to see the Civil War.

Blaine—he was born in 1797 and died in 1860—did not live to see the Civil War.

Blaine (1797-1860) did not live to see the Civil War.

Sometimes the choice is clear. For instance, you’d never see this sentence: Blaine—1797-1860—did not live to see the Civil War. But it is also true that a writer’s use of one of these marks instead of another is often a matter of personal taste.

Parentheses can be used to form a separate sentence, as here: I hoped my friend was coming. (He canceled at the last minute.) But the writer could also have done this: I hoped my friend was coming (he canceled at the last minute). Note the placement of the period; if parentheses end a sentence, the period goes after the closing parenthesis.

Commas virtually always follow parentheses rather than precede them. This sentence is incorrect: When he got home, (it was already dark outside) he fixed dinner. Make it When he got home (it was already dark outside), he fixed dinner.

Writers have a lot of leeway with parentheses, as long as they heed a few simple guidelines. Used shrewdly (and sparingly!), parentheses add color, nuance, and spice to your writing.


Pop Quiz

Correct any sentence that needs it.

1. When Tony showed up, (he was right on time) we had a long talk.

2. Do not exceed 25 mph (you will be cited.)

3. After the hike, Mark took a long drink of water (he really needed it!)


Pop Quiz Answers

1. When Tony showed up (he was right on time), we had a long talk.

2. Do not exceed 25 mph (you will be cited).
OR Do not exceed 25 mph. (You will be cited.)

3. After the hike, Mark took a long drink of water (he really needed it!).
OR After the hike, Mark took a long drink of water. (He really needed it!)

If the article or the existing discussions do not address a thought or question you have on the subject, please use the "Comment" box at the bottom of this page.

19 responses to “(All About) Parentheses”

  1. Randy Bass says:

    It wasn’t stated, but if the ending punctuation is a question mark or exclamation mark, it goes inside the parenthesis, even if the parenthetic expression is part of a larger sentence, with a period for the sentence outside of the closing parenthesis, as was the case with the first alternative answer to 4.

  2. Julia Emerson says:

    I have been told (indicating) is a “stand alone phrase,” and I’m supposed to put the punctuation inside the parentheses; is this correct?

    A. The defendant is sitting at counsel’s table (indicating.)

    A. My car was here (indicating,) and his car was here.

    • Our rules for punctuating with parentheses can be found on the Parentheses and Brackets page. Rule 1 says, “If material in parentheses ends a sentence, the period goes after the parentheses.” Rule 2 says “Periods go inside parentheses only if an entire sentence is inside the parentheses.” However, your sentence sounds like an excerpt from a legal document. Different rules might apply. We recommend consulting either The Bluebook: A Uniform System of Citation, published by the Harvard Law Review Association or the ALWD Citation Manual: A Professional System of Citation, prepared and published by the Association of Legal Writing Directors and Darby Dickerson.

  3. Andy says:

    What is the proper way to punctuate a question about a quote that is referenced in parentheses?

    For example is the following punctuated properly,
    Are you committed to the principle of “Whatever you would want men to do to you, do also to them,” (Matthew 7:12)?

    If the above is not correct, please suggest a correct way.

    • We recommend:
      Are you committed to the principle, “Whatever you would want men to do to you, do also to them” (Matthew 7:12)?

      • Timotheos Zmudski says:

        Would a colon have worked?
        Are you committed to the principle: “Whatever you would want men…”

        If not, would it be correct if written
        Are you committed to the following principle: “Whatever you would want men…”

        Or can colons only be used to signify a list of some sort?

        • says:

          Our Rules for Colons says, “A colon means ‘that is to say’ or ‘here’s what I mean.’ ” Therefore, your second example sentence is acceptable; however, a colon would not be appropriate in the first one.

  4. Dena Fischer says:

    When noting a rule such as “…compensation (within the meaning of ERISA Section 408(b)(2) and Internal Revenue Code Section 4975(d)(2),” Should there be a ‘closing’ parenthesis?

    “…compensation (within the meaning of ERISA Section 408(b)(2) and Internal Revenue Code Section 4975(d)(2)),”

    • Our post Use of Brackets says, “Use brackets as parentheses within parentheses. You will see this with bibliographic references.” Therefore, we recommend writing the following:
      “…compensation (within the meaning of ERISA Section 408[b][2] and Internal Revenue Code Section 4975[d][2]),”

  5. Jose Ballester says:

    I am hoping you can help me with the following sentence.
    “With our bodily eyes we shall see the humanity of Jesus, God reflected in creatures, etc. (i.e., natural beatitude).”
    This is not so much about the particular sentence, I suppose it could be better written. But there is an ‘etc.’ which ends in a period, then there is a parenthesis. In such a case there is a period after the ‘etc.’ and another period after the parenthesis, correct? But this would seem to violate the rule against a period after an abbreviation with a period. My guess is that the sentence should stand as written, with a period after ‘etc’ and a period after the parenthesis. Am I correct?

    • Your punctuation is correct. You are not violating any punctuation rule because of the presence of the parenthetical expression at the end of your sentence. In this sentence, we use only one period because it ends with etc.

  6. Linda Gurganus says:

    I teach mathematics at a university in the southeastern part of the US. I find that many of our lecturers use “parenthese” (with a long e at the end) to refer to the singular parenthesis. I have tried to correct them, but they are sure it is no big deal and persist in this.

  7. Theresa Lui says:

    Since the rules state that phrases or clauses can be separated in a sentence with commas, dashes, or parentheses, how do you determine which is the best one in a sentence? What exactly is the difference among the three?

  8. Maurita says:

    I enjoyed this blog; I really liked the breakdown that it provided as to when and how to use parentheses opposed to commas and long dashes. I was already familiar with the rule to put the period after the parentheses in a sentence. I will say that I, myself, have not seen a sentence where a period ended the sentence and then there is a second period inside the parenthesis; for example: Do not exceed 25 mph. (You will be cited.)
    I usually only see the period placed after the parentheses. So that is something new I learned in this blog- that parentheses can be used to form a separate sentence.

  9. Jane Sun says:

    In the sentence “I gave up what might have been a magnificent career as a painter” from The Little Prince, is “what might have been” a parenthesis?
    Some teacher said that “what might have been… a painter” is an object noun. What’s more, from the article above, it is not a parenthesis. Am I right, or are there any parentheses without any punctuation? Thanks!

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