Punctuation

A. Yes, it can . . . But keep in mind that there are at least two ways to use an ellipsis. In the first of these, an ellipsis represents a lapse of some sort—for example, a faltering, a trailing off, or a pause. For that kind of ellipsis, use only three dots wherever the ellipsis occurs (as at the start of this answer).

But when the dots represent an omission within a quotation, retain a period at the end of a grammatically complete sentence. Put this period before the ellipsis, even if that’s not where the sentence ends in the original source: “Vanity and pride are different things. . . . Pride relates more to our opinion of ourselves, vanity to what we would have others think of us” (Jane Austen, Pride and Prejudice).

A. We wouldn’t say always. In writing that is both formal and technical, contractions are still generally discouraged (as you will find, for example, in the latest editions of Scientific Style and Format and the style manual of the American Medical Association). But in nontechnical contexts, any rule against using contractions works against writing that sounds natural and is therefore easy (or at least pleasant) to read. Chicago therefore doesn’t prohibit them. What’s more, the first edition (published in 1906, in the era of spats) included a few (and not only as examples demonstrating how an apostrophe is used). Here’s one: “Don’t stultify yourself and discredit the office by asking foolish questions on the proof” (p. 99). That advice might just as well apply to contractions: “Don’t stultify yourself by avoiding the apostrophe.” As for the phrase “what’s more,” if the apostrophe bothers you (or if it’s forbidden by your style guide), try “furthermore” instead.

A. The nice thing about using an apostrophe to help form a plural is that it does it so well; you’d never know that it was born under questionable circumstances, or that it doesn’t have a right to play that role. You’ll find it in Shakespeare: “By my life this is my Ladies hand: these bee her very C’s, her V’s, and her T’s, and thus makes shee her great P’s. It is in contempt of question her hand” (Twelfth Night, act 2, scene 5 [1st folio, 1623]; and note the absence of an apostrophe, and the plural ending, in the possessive “Ladies”). In its first eleven editions, CMOS advised writing “the three R’s,” after which it became “the three Rs.” But the intent of the rule has remained the same: use an apostrophe wherever it is needed to prevent a misreading. And as anyone who got A’s in chemistry (or knows their Agatha Christie) might tell you, sometimes an apostrophe can spell the difference between a letter grade and a poison.

A. First, don’t use a question mark immediately followed by a colon, or vice versa (neither :? nor ?:); instead, use the stronger mark. Assuming a direct question, the question mark is usually stronger.

Which fruit would you be most likely to recognize by texture alone?

banana
apple
blueberry
cherry
pineapple

A signal like “the following” can be helpful in such cases: “Which of the following fruits . . .”

If you incorporate the list into a sentence, the question mark can follow the last item.

Which fruit would you be most likely to recognize by texture alone: bananas, apples, blueberries, cherries, or pineapples?

Especially for shorter sentences, a comma can be used instead of a colon to introduce the list.

Which fruit do you like best, bananas or pineapples?

but

Do you prefer apples or bananas or blueberries? [See CMOS 6.67.]

A. “DC” (no periods) is the official postal abbreviation, in use since October 1963, when the US Post Office Department (now the US Postal Service) introduced its list of two-letter abbreviations for states and territories (and the District of Columbia). The Chicago Manual of Style now recommends these familiar two-letter forms over the traditional abbreviations. So we recommend not only “DC” rather than “D.C.” but also, for example, “IL” rather than “Ill.” Chicago’s preference for “US,” on the other hand, accords with established usage for other countries (the UK, the former USSR, the PRC) and for most other initialisms and acronyms that take full capitals (NASA, UN, DNA). It is true that many publications still favor the more traditional forms with periods, and those are not wrong. But it would be wrong to suggest that kids can’t learn to appreciate the details that make reading (and editing) so interesting.

A. We don’t have an official stance on double question marks. But to invoke the spirit of CMOS if not the letter, you might keep in mind that any kind of emphasis tends to lose its effectiveness if overdone. This is essentially our stance on exclamation points (see CMOS 6.71), advice that’s equally applicable to doubled question marks.

A. The periods are certainly awkward when it comes to putting that title into a sentence. But for better or for worse, they’re part of the title’s personality, so it’s probably best to leave them as they are. If the title appears midsentence, omit the final period or change it to a comma, depending on the syntax. Try to think of the whole thing as a unit and just avert your eyes.

A. Hang on! We’re coming! You are right: quotation marks are irrelevant. The inches symbol must be closed up to the number, which puts the period at the very end, after the entire expression: 4″ × 5″. Also, please note that the symbol for inches is the double prime (″), not double quotation marks  (”) or straight quotation marks (") or (gasp!) two single quotation marks in a row ('').

A. It depends. In a work where all the ellipses mean that the writer has omitted a part of the original when quoting, readers will understand what’s going on and there’s no need for brackets. It gets tricky if the same document quotes from an original that has an ellipsis in it. That means there are two kinds of ellipses, and they need to be distinguished somehow. And that’s when brackets are used for the author’s own ellipses. (Sometimes it’s a good idea to explain this method to your readers.) An alternative is to skip the brackets and write “(ellipsis in original)” when needed.

A. No period; just use the ellipsis. This is covered at CMOS 13.55 (“Ellipses at the Ends of Deliberately Incomplete Sentences”).