Parentheses

Parentheses differ from em dashes and commas in that they usually set off material that is less closely related to the rest of the sentence. There are a few rules that pertain to the use of parentheses.

With em Dashes

A combination of parentheses and em dashes may be used if called for.

• The conference—it had already been interrupted by three demonstrations (to the chagrin of the professor)—was adjourned promptly.

Parentheses Within Parentheses

Generally, in regular writing, try to avoid doing this. This is saved mainly for bibliographical purposes, and when doing so, use brackets within the parentheses to avoid confusion.

With Other Punctuation

Punctuating within parentheses is very particular.

• If the entire sentence is within the parentheses—and it is not incorporated within another sentence—punctuate the sentence properly within the parentheses.
• If the parenthetical material falls completely within another sentence, follow these rules:
• Commas, periods, colons, and semicolons follow the closing parenthesis.
• A question mark, exclamation point, and closing quotation mark precede the closing parenthesis if they belong to the parenthetical material; they follow if they belong to the surrounding sentence.
• A parenthetical enclosure should not include more than one sentence. (If it is necessary, rewording may be needed so as to create a parenthetical sentence independent of another sentence, such as this one.)
• Different kinds of material may be included in a single set of parentheses, usually separated by a semicolon.
• Examples:
• Having entered the room (on tiptoe), they quietly got into their beds.
• Come on in (quietly, please!) and take a seat.
• They entered the room and took a seat (she had a feeling they were a little early; the professor still hadn't arrived).
• Finally relaxing after a long day (Ron still hadn't gotten the hang of being an Auror and didn't think he ever would), he showered, ate, and went to bed.
• She closed her eyes and wished for the best (hoping for an "O"); then, she opened them and looked at the test scores along with everyone else.