Parentheses may be used in formal writing to add supplementary information , such as `` Sen. John McCain ( R. , Arizona ) spoke at length . ''
Parentheses may be used in formal writing to add more information , such as in : `` Sen. John McCain ( R. , Arizona ) spoke at length '' They can also note `` either singular or plural '' for nouns , such as in the word `` claim ( s ) '' .