Uses of Parentheses

Setting off incidental information

Parentheses are used to enclose incidental information, such as a passing comment, a minor example or addition, or a brief explanation. As with the dash, the decision to use parentheses is your judgment call. Sometimes commas or dashes might be a better choice.

• Some of the local store owners (Mr. Kwan and Ms. Lawson, for example) insisted that the street be widened,

• OR   Some of the local store owners— Mr. Kwan and Ms. Lawson, for example—insisted that the street be widened.

• Roger Worthington ( a poorly drawn character in the novel) reveals the secret in the last chapter.

• OR   Roger Worthington, a poorly drawn character in the novel, reveals the secret in the last chapter.

Other punctuation marks with parentheses

Don't put any punctuation mark before parentheses, and put a comma after the closing parenthesis only if your sentence would call for the comma anyway.

• Use a pointed stick (a pencil with the lead point broken off works well) or a similar tool.

No comma appears before or after the parentheses. If you were to remove the parenthetical remark, the remaining sentence would not need a comma: Use a pointed stick or a similar tool.

• Banging the wall and screaming (unrestrained by his father, I might add), Sam was acting like a brat.

In the preceding sentence, no comma appears before the parentheses. A comma follows the parentheses because if you were to remove the parenthetical comment, the remaining sentence would require a comma: Banging the wall and screaming, Sam was acting like a brat.

Punctuation within parentheses

If your parentheses enclose a sentence-within-a-sentence, don't use a period within the parentheses. Do, however, use a question mark or an exclamation point if it is called for.

• Mother love (hers was fierce) ruined the young boy's life.

• They finally said (why couldn't they have admitted it earlier?) that she had been there.

• The wedding reception (what a fiasco!) ended abruptly.

If the parentheses enclose a complete sentence that stands alone, keep the period within the parentheses.

• (Her father was the only one who didn't attend.)

Miscellaneous uses of parentheses

You'll need to learn how to use parentheses in special situations. For example, use parentheses to enclose a date or a citation.

• Sir William Walton (1902–1983) composed the oratorio Belshazzar's Feast.

• According to the reports of her contemporaries, she was a mediocre critic and a worse artist (Travis, 26–62).

In scientific, business, or legal writing, parentheses are used to restate a number. Be sure this use is justified. In most prose, it is not, and it creates an inappropriately official tone.

• The bill is due and payable in thirty (30) days. (acceptable)

• My grandfather knew my grandmother for sixty (60) years. (not appropriate)

When to use brackets

Brackets are a special case and are used in specific situations. Use brackets to insert something into a sentence that is already in parentheses.

• (Don't forget, however, that the joints will be filled with grout [see page 46].)

Also use brackets when you want to insert an explanatory word or note within a quotation.

• “Mel [Gibson] is one of my best customers,” the street vendor bragged.