By the way
Yesterday on Twitter @CopyCurmudgeon set off a brief exchange on parentheses: I'd rather have too many em dashes than too many parentheticals. Parentheses say, "Ignore me (I don't matter)."
Responses came quickly from @Your_Wordsworth, Sometimes they're just an aside. But if the aside is important, it probably shouldn't be in parentheses* and @JuneCasagrande, Parentheses can be a 'dis to reader, too, cramming in info the writer was supposed to weave into digestible narrative.
So I thought, prone as I am to drifting off-topic in mid-sentence, I might clarify a little about parentheticals.
The most common parentheticals are appositives and other phrases or clauses set off by commas: His wife, whose first husband went out for cigarettes one night and never came back, is an accomplished cook whose coq au vin has been the centerpiece of many holiday meals.
Parentheses function as asides do in speech—you know, turning your head slightly and dropping your voice. His editing (they say he’s known to take a drink in the daytime) gets increasingly erratic by midafternoon.
And the em dash, with spaces on either side or not, as your house style dictates, is intended to indicate a sharp break in continuity: They don’t understand production, they make a dog’s breakfast of the coding, they might make deadline if they learned to tell time, and—damn, I didn’t think they could hear me.
You notice that this sequence, commas, parentheses, dashes, is a pattern of increasing interruption of the flow of the text. But not everyone honors it.
Newspaper journalists are in the unfortunate habit of using parentheses where brackets would be appropriate for interpolated information, a nasty habit encouraged by the Associated Press. And they are so dash-happy that they use dashes all the time and everywhere, cluttering the page and diluting the effect.
If you’re an editor, experiment with replacing the reporter’s em dashes with commas. I think you’ll find that it makes the text easier to read and also gains you a few lines when you need to cut.