Dashes Exercise (450)
Change the punctuation in the following sentences, adding or removing dashes, to make the sentence structure clearer.
Answers and Explanations
Original: I opened the door and voilà, John was standing there.
Correct : I opened the door and—voilà!—John was standing there.
A parenthetical interjection (a word or phrase that provides additional information but can be excised from a sentence without compromising the grammatical structure of the sentence) must be both preceded and followed by punctuation. Also, use dashes, not commas, to indicate a sudden break in the syntax of a sentence. In addition, employ an exclamation point for exclamations. Without these two punctuation strategies, an attempt to evoke surprise will fall flat.
Original: Previously, Internet advertisers could pique surfers’ interests with display ads, that is with the power of suggestion, but now Internet users largely ignore those ads.
Correct : Previously, Internet advertisers could pique surfers’ interests with display ad—that is, with the power of suggestion—but now Internet users largely ignore those ads.
Because the tag phrase "that is" must be set off from "with the power of suggestion," and those two phrases constitute a parenthetical interjection, separate the two phrases with a comma and use dashes to set the combined interjection off from the rest of the sentence. (Using commas to set "that is, with the power of suggestion" off would confuse readers because of the additional comma after "that is.")
Original: He definitely sticks up for women, for anyone really.
Correct : He definitely sticks up for women—for anyone, really.
As a nonessential tag word, "really" must be set off with a comma. And because "for anyone, really" is an abrupt syntactical change from the preceding part of the sentence, a simple comma is not sufficient to signal that break, so a dash is required. ("For anyone, really" could also be set off within parentheses, but that weakens the impact of the phrase.) Compare with the previous item; "for anyone, really" is a parenthetical interjection that happens to come at the end of the sentence, rather
Original: The fluid rivers in the body must also flow freely to bring good things—oxygen, healing nutrients, healing cells—in and take harmful things—toxins, pathogens, inflammatory cells and chemicals—away.
Correct : The fluid rivers in the body must also flow freely to bring good things (oxygen, healing nutrients, healing cells) in and take harmful things (toxins, pathogens, inflammatory cells and chemicals) away.
Do not use more than one pair of dashes in a sentence; doing so confuses the reader about which words or phrases are interjections. Instead, when interjecting more than one parenthetical within the same sentence, use parentheses (which, because of their shape, visually clarify what they are enclosing). Another alternative is to divide the sentence into two statements and retain the dashes, but it is more concise as is.
Original: One in four of the world’s species of mammals is facing extinction—and the numbers are significantly greater for the large mammals that humans most identify with—primates, ocean mammals, big cats, and others.
Correct : One in four of the world’s species of mammals is facing extinction—and the numbers are significantly greater for the large mammals that humans most identify with: primates, ocean mammals, big cats, and others.
Do not nest dashes, so that in the phrase following a dash, another subordinate phrase follows another dash. Use alternate forms of punctuation so that only one dash is used. (Parentheses are also correct, but they suggest that the content within them is not that important; preceding the list with a colon is more forceful.)