Parentheses and long dashes may be used, but should be deployed sparingly to preserve their impact on the audience.
Parentheses should be used to add a comment relating to the preceding clause as an aside. Imagine you are telling this story to your friends; would you mumble this remark under your breath? Then use parentheses.
Long dashes should be used to add a comment relating to the preceding clause that you want to emphasize. If you were telling this story to your friends, would you stop mid-sentence and maybe raise your voice to underline your point? Then use a long dash.
In quotes, use parentheses to replace unclear or misstated words, or to add missing information: “Barry (Sanders) will practice (Thursday) and should be ready to go for Sunday’s game ,” Lions coach Wayne Fontes said.
Brackets have no application.
