Uses of Parentheses

Parentheses are a pair of signs ( ) helpful in marking off text. You use parentheses in specific situations that can be covered by a few simple guidelines.

Setting off incidental information

Parentheses are used to enclose incidental or extra information, such as a passing comment, a minor example or addition, or a brief explanation. The writer may choose to put additional information within parentheses or to set off the text using dashes or commas. Again, overuse of parentheses or dashes can be distracting to readers.

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 the sentence needs a 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 the parenthetical comment is removed, the rest of the 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 use a question mark or an exclamation mark if it is called for.

Mother love ( hers was fierce) ruined the young boy's life.
They finally said ( why didn't they admit it earlier?) that she had been there.
The wedding reception ( what a fiasco!) ended abruptly.

If the parentheses enclose a complete sentence that can stand alone, place the period inside the closing parentheses.

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

If the parentheses enclose a phrase that falls at the end of the sentence, place the closing punctuation outside the closing mark.

The only one who didn't attend was Mr. Jensen ( her father).

Miscellaneous uses of parentheses

You should 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. However, in most writing, it is not justified, and it creates an overly 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 only used in specific situations. Use brackets to insert something into a sentence that is already enclosed 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.

“Bill and Melinda [ Griffin] are two of my best customers,” the street vendor bragged.