Abbreviations. Do not break abbreviations over lines, regardless of their internal capitalization, punctuation, and spacing (BA, U.S., NATO, p.m., kg, PhD, Gov. Gen.). The only exception is that an abbreviation that already includes a hyphen, such as AFL-CIO, may be divided on the hyphen. See chapter 24 for more on abbreviations. Punctuation. Never begin a line with a closing quotation mark, parenthesis, or bracket. Never end a line with an opening quotation mark, parenthesis, or bracket or with (a) or (1), as at the beginning of a list. See chapter 21 for more on punctuation and 23.4.2 for lists. Avoid breaking an ellipsis (see 25.3.2) over a line; use your word processor's ellipsis character to prevent this problem. URLs and e-mail addresses. Avoid breaking URLs and e-mail addresses over lines. If you have to break one, insert the break after a colon, a slash (or double slash), or the symbol @ but before a period or any other punctuation or symbols. Hyphens are frequently included as part of a URL or e-mail address, so to avoid confusion, never add a hyphen to indicate the break, or break a URL or address at an existing hyphen. http:// www.press.uchicago.edu http://www .press.uchicago.edu http://www.press.uchicago.edu/ cgi-bin/hfs.cgi/00/12917.ctl If your word processor automatically formats URLs and e-mail addresses as hyperlinks, it may break these items contrary to the guidelines above. In many settings, such breaks are acceptable as long as the full URL or address is clearly identified as a hyperlink (through underlining or a second color) and no extra hyphens are added to indicate the line breaks. 21 Punctuation 21.1 Period 21.2 Comma 21.2.1 Independent Clauses 21.2.2 Series 21.2.3 Nonrestrictive Clauses and Phrases 21.2.4 Other Uses www.itpub.net 21.3 Semicolon 21.4 Colon 21.5 Question Mark 21.6 Exclamation Point 21.7 Hyphen and Dashes 21.7.1 Hyphen 21.7.2 Dash 21.7.3 Multiple Dashes 21.8 Parentheses and Brackets 21.8.1 Parentheses 21.8.2 Brackets 21.9 Slashes 21.10 Quotation Marks 21.11 Multiple Punctuation Marks 21.11.1 Omission of Punctuation Marks 21.11.2 Order of Punctuation Marks This chapter offers general guidelines for punctuation in the text of your paper. Some rules are clear-cut, but others are not, so you often have to depend on sound judgment and a good ear. Special elements such as abbreviations, quotations, and citations have their own guidelines for punctuation, which are treated in relevant chapters in this book. If you are writing a thesis or dissertation, your department or university may have specific requirements for punctuation, which are usually available from the office of theses and dissertations. If you are writing a class paper, your instructor may also ask you to follow certain principles for punctuation. Review these requirements before you prepare your paper. They take precedence over the guidelines suggested here. For style guides in various disciplines, see the bibliography. 21.1 Period A period ends a sentence that is a declarative statement, an imperative statement, or an indirect question. A period can also end a sentence fragment, if the context makes its rhetorical function clear. But this usage is rare in academic writing. In all these cases, the period is a terminal period and should be followed by a single space. Consider the advantages of this method. The question was whether these differences could be reconciled. Put a period at the end of items in a vertical list only if the items are complete sentences (see 23.4.2). Otherwise, omit terminal periods, even for the last item, and do not capitalize the first words. The report covers three areas: 1. the securities markets 2. the securities industry 3. the securities industry in the economy Individual periods can also be used in other contexts, including abbreviations (see especially 24.1.3) and citations (16.1.2 and 18.1.2), and also in URLs (20.4.2, 17.1.7, and 19.1.8), where they are often called dots. Strings of periods, or dots, can be used in quotations (see 25.3.2), where they are called ellipses, and in tables (26.2.6) and front matter pages (A.2.1), where they are called leaders. Do not use periods after chapter and part titles and most subheadings (see A.2.2) or after table titles (26.2.2). For periods in figure captions, see 26.3.2. 21.2 Comma Commas separate items within a sentence, including clauses, phrases, and individual words. They are especially important when a reader might mistake where a clause or phrase ends and another begins: Before leaving the members of the committee met in the assembly room. www.itpub.net Before leaving, the members of the committee met in the assembly room. For use of commas in numbers, see 23.2.2. For use of commas in citations, see 16.1.2 and 18.1.2. 21.2.1 Independent Clauses In a sentence containing two or more independent clauses joined by a coordinating conjunction (and, but, or, nor, for, so, yet), put a comma before the conjunction. This is not a hard-and-fast rule; no comma is needed between two short independent clauses with no internal punctuation. Students around the world want to learn English, and many young Americans are eager to teach them. The senator arrived at noon and the president left at one. In a sentence containing three or more short and simple independent clauses with no internal punctuation, separate the clauses with commas and add a coordinating conjunction before the last one. (Always include a comma before the coordinating conjunction.) If the clauses are longer and more complex, separate them with semicolons (see 21.3)—or, better, rewrite the sentence. The committee designed the questionnaire, the field workers collected responses, and the statistician analyzed the results. The committee designed the questionnaire, which was short; the field workers, who did not participate, collected responses; and the statistician analyzed the results, though not until several days later. Ordinarily, do not insert a comma before a conjunction joining two subjects or two predicates. The agencies that design the surveys and the analysts who evaluate the results should work together. They do not condone such practices but attempt to refute them theoretically. When a sentence opens with a phrase or dependent clause that modifies following two independent coordinate clauses, put a comma after the introductory element but not between the two independent clauses. Within ten years, interest rates surged and the housing market declined. 21.2.2 Series In a series consisting of three or more words, phrases, or clauses with no internal punctuation of their own, separate the elements with commas. Always use a comma before the conjunction that introduces the last item. The governor wrote his senators, the president, and the vice president. Attending the conference were Fernandez, Sullivan, and Kendrick. The public approved, the committee agreed, but the measure failed. Do not use commas when all the elements in a series are joined by conjunctions. The palette consisted of blue and green and orange. If a series of three or more words, phrases, or clauses ends with an expression indicating continuation (and so forth, and so on, and the like, or etc.), punctuate that final expression as though it were the final item in the series. You may, however, add a comma after the continuation expression to prevent confusion after a long series. They discussed movies, books, plays, and the like until late in the night. Management can improve not just productivity, but hours, working conditions, training, benefits, and so on, without reducing wages. Use semicolons to separate the items in a series if one or more includes commas, or if the items are long and complex (see 21.3). If such a series comes before the main verb of a sentence, however, rephrase the sentence. The three cities that we compare are Hartford, Connecticut; Kalamazoo, Michigan; and Pasadena, California. but not Hartford, Connecticut; Kalamazoo, Michigan; and Pasadena, California, are three cities worth comparing. 21.2.3 Nonrestrictive Clauses and Phrases Use paired commas to set off a nonrestrictive clause. A clause is nonrestrictive if it is not necessary to uniquely identify the noun it modifies. These five books, which are on reserve in the library, are required reading. Here, the noun phrase These five books uniquely identifies the books that the writer has in mind; the nonrestrictive clause is not necessary to identify the books further. On the other hand, in the following sentence, the dependent clause (that are required reading) is restrictive, because it identifies the specific books that are required reading. Commas are therefore not used around the clause. The books that are required reading are on reserve in the library. Although which is often used with restrictive clauses, careful writers preserve the distinction between restrictive that (no comma) and nonrestrictive which (comma). The same principles apply to restrictive and nonrestrictive phrases. The president, wearing a red dress, attended the conference. The woman wearing a red dress is the president. 21.2.4 Other Uses Commas are used in a variety of other situations. (For use of commas in dates, see 23.3.1.) Introductory words and phrases. When you begin a sentence with an introductory www.itpub.net element of more than a few words, follow it with a comma, especially if a slight pause normally occurs in speech.