Parentheses enclose peripheral or nonessential information. If the enclosed words are not a complete sentence, punctuate as follows:
Only three people (the interns in the development office) failed to show up for the meeting.
In college Marla had multiple majors (and no free time).
If a complete sentence is enclosed in parentheses, it can either appear as part of another sentence or stand apart on its own. The following examples illustrate proper punctuation and capitalization of a parenthetical sentence:
I don’t have time to talk now (the meeting begins in five minutes) and probably won’t be free until late afternoon.
If you would like a copy of the manuscript (my assistant has an extra one), I would be glad to mail it to you.
I ran out of time. (Joan, on the other hand, ran out of energy.)
Often in a report or other document, writers make reference to various charts and exhibits. Both of the following approaches are acceptable:
GNP rose dramatically during that period (see Table 2).
GNP rose dramatically during that period. (See Table 2.)
Be careful not to overuse parentheses, as an abundance of them can make your writing sound choppy. If you have quite a few parentheses in a document, you may be including too much information that is only marginally relevant to the document’s purpose. If an idea doesn’t really further your goal in writing, you can simply remove it.
Alternatively, if the material in parentheses is directly relevant, you might consider removing the parentheses and integrating the material more fully with the rest of your text.