Parentheses separate inessential information from the rest of the sentence. Use these nice little marks to make editorial comments, to clarify a point, and to isolate clarifications or editorializing from the rest of the sentence.
Some writers stumble a bit on how to punctuate within or around parenthesis. Well, itís simple. The surrounding sentence must read grammatically correctly if the parenthesized section is removed. For this reason, punctuation goes outside the parenthesis most of the time.
Here are some sentences where the punctuation goes outside because the parenthetical section is not part of the sentenceís structure.
Using a hyphen (-), he made a compound word.
The sleepy girl yawned (without covering her mouth).
Five of the fourteen crayons (that remained after the childís waxy snack) were the same shade of blue.
Punctuation goes outside the parenthesis unless the punctuation is only part of the parenthesized section. Hereís a sample where thereís a bit of both inside and outside punctuation, depending on whether the punctuation goes with the sentence proper or with the parenthetical section.
Rugby follows different rules than soccer (most other languages call soccer ďfootballĒ).
And hereís an example where the parenthetical comment is a complete sentence and is separate from the other sentence.
There are three birds outside my window. (They are a scrub jay and two junko finches.)
See the difference? Where the period is within the parentheses, there is a complete sentence that is entirely separate from the preceding sentence. (The completely parenthetical sentence also starts with a capital letter, as does this sentence that youíre reading.)
When you have a parenthetical segment and you need to have another parenthetical segment within it, use square brackets. Like this:
The most important thing (to this discussion, anyway [and according to me]) is writing clearly.
The only times you use square brackets is within parentheses, like the previous example, or to denote altered text in a quotation.
The little rabbit ran as fast as [he] could to escape the farmerís shovel.
Use the square brackets to show that you have altered the authorís text, or that you are disclaiming the authorís mistakes by using the Latin word sic enclosed in square brackets.
Thatís pretty much all there is to parenthesis. Oh, except try to keep their use to a dull roar. If you (like me) find yourself whispering behind your hand a lot by using parenthesis, youíre probably including more tangents than you really need to. (Thatís an easy trick you can use to remember what makes parenthesis so special; they kind of look like a hand you might be whispering behind, donít they?)