Parentheses are similar to commas in that they set off information that further explains or enhances a statement. Information that is very closely related to the statement should be set off with commas; information that is more incidental should be set off with parentheses.
I tried to get to the elevator before the door shut, but I was too slow.
Most of my favorite authors (Shakespeare, Dickens, Woolf) are dead.
Expressions beginning with i.e., e.g., that is and so on can be set off with parentheses if they cause a major break in the sentence. If the break is minor, use commas.
He interviewed the biggest stars of the day, namely, Madonna, Michael Jackson, and Jack Nicholson.
Classic works of literature (e.g.,Dickens, Shakespeare, the Brontes) lined the shelves.
If the contents of the parentheses include at least one complete sentence, the period goes inside the parentheses. If not, the period goes outside.
