Peculiarities of prose style

or mild interjection) from the rest of the sentence:

If you refuse to leave, I'll call the police. (clause)

To prepare for her exam, Lynn reread all of her notes. (phrase)

Nevertheless, much work still remains to be done. (conjunctive adverb)

Well, I was surprised to achieve these results. (interjection)

1.3 (a) Use commas to set off parenthetical elements or interrupters (including transitional adverbs):

The report, which was well documented, was discussed with considerable emotion. (nonrestrictive clause)

They were, however, still able to meet their deadline.(transitional adverb)

An important distinction must be made here between restrictive and nonrestrictive modifiers. Restrictive modifiers are essential to the meaning of the sentence in that they restrict that meaning to a particular case. Hence, restrictive modifiers are not parenthetical and cannot be removed without seriously damaging the meaning. Since they are necessary to the meaning, restrictive modifiers are not set off by commas:

All soldiers who are overweight will be forced to resign.

Nonrestrictive modifiers are parenthetical. That is, they digress, amplify, or explain, but are not essential to the meaning of the sentence. These modifiers simply provide additional information for the reader—information which, although it may be interesting, does not restrict the meaning of the sentence and can be removed without changing the sentence's essential meaning:

Sgt. Price, who is overweight, will be forced to resign.

(b) Use commas to set off parenthetical elements that retain a close logical relationship to the rest of the sentence. Use dashes or parentheses to set off parenthetical elements whose logical relationship to the rest of the sentence is more remote (compare 4.2 and 5.1).

1.4 Use commas to join items in a series. Except in journalism, this includes a comma before the conjunction that links the last item to the rest of the series:

Before making a decision, he studied the proposition, interviewed many of the people concerned, and tried to determine if there were any historical precedents.

1.5 Although not called for by any of the above principles, commas are sometimes required to avoid the confusion of mistaken junction:

She recognized the man who entered the room, and gasped.

2. Semicolons

2.1 Use a semicolon to join two independent clauses that are closely related in meaning and are not joined by a coordinating conjunction (compare 1.1):

A filemode digit of 3 identifies a temporary file; temporary files are deleted automatically after being read.

2.2 Use a semicolon to join two independent clauses when the second one begins with or includes a conjunctive adverb (nevertheless, therefore, however, otherwise, as a result, etc.) (compare 1.3):

If CMS is waiting, the entry will be processed immediately; otherwise, it will be queued until requested.

2.3 To avoid confusion, use semicolons to separate items in a series when one or more of the items includes commas (see also 1.1c):

This manual also summarizes the Graduate School's mechanical requirements for theses; discusses the special requirements of students who are submitting computer programs as theses; reviews basic principles of punctuation, mechanics, and style; and refers student s to standard references on punctuation, mechanics, style, and usage.

3. Colons

3.1 Use a colon to introduce a list, an example, an amplification, or an explanation directly related to something just mentioned (compare 4.1) and 4.4):

The user may work from one of three modes when typing data into the file area: edit mode, input mode, or power typing. He eventually found that there was only one way to get the quality he expected from the people who worked for him: treat them with respect.

3.2 Use a colon to introduce a formal statement or quotation (usually of more than one line):

Writers who care about the quality of their work would do well to heed Samuel Johnson's advice: What is written without effort is in general read without pleasure.

4. Dashes

If your word-processor doesn't have an em-dash (a dash that is the width of a capital M) in its special character set, use two hyphens (--) to make a dash. Whichever one you use, except in journalism, you should leave no space between or on either side of the dash itself. Dashes are more widely accepted today than they were in the past; however, many writers and editors still consider them to be somewhat less formal marks of punctuation—use them sparingly.

4.1 Use a dash to introduce a summarizing word, phrase, or clause, such as an appositive (a noun set beside another noun and identifying or explaining it) (compare 3.1):

The strikers included plumbers, electricians, carpenters, truck drivers—all kinds of workers.

4.2 Use dashes to mark off a parenthetical element that represents an abrupt break in thought. Dashes give more emphasis to the enclosed element than do either commas or parentheses (compare 5.1):

Reagan's sweep of the South—he won every state but Georgia—was the most humiliating defeat for Carter.

4.3 To avoid confusion, use dashes to mark off parenthetical elements that contain internal commas:

Seven of our first twelve presidents—Washington, Jefferson, Madison, Monroe, Harrison, Tyler, and Taylor—were from Virginia.

4.4 Dashes can be used as a less formal alternative to the colon to introduce an example, explanation, or amplification (see 3.1).

For more on the use of dashes in journalism, see the entry on dashes in the Guide to Punctuation in the Associated Press Stylebook.

5. Parentheses

5.1 (a) Use parentheses to enclose parenthetical elements (words, phrases, or complete sentences that digress, amplify, or explain) (compare 1.3b) and 4.2).

When APL is on (indicated by the letters APL appearing at the bottom of the screen), no lower-case characters are available.

(b) A parenthesized sentence that appears within another sentence need not begin with a capital or end with a period.

5.2 Except in journalism, use square brackets [ ] to enclose a parenthetical element within a parenthetical element.

6. Ellipsis Dots

6.1 Use three dots

(a) to signal the omission of a word or words from the middle of a quoted sentence:

A senior White House official again asserted the administration's position: "We will not negotiate any treaty with the Soviets . . .unless it is verifiable."

(b) to signal hesitation or halting speech in dialogue:

"I . . . don't know what to say," he whispered.

6.2 Use four dots

(a) to signal the omission of the end of a quoted sentence:

"Of all our maladies, the most barbarous is to despise our being. . . . For my part, I love life and cultivate it."

— Montaigne

(b) to signal the omission of one or more whole sentences.

Except in journalism, ellipses dots should be spaced ( . . . vs. …).

7. Hyphens

7.1 To express the idea of a unit and to avoid ambiguity, hyphenate compound nouns and compound modifiers that precede a noun:

She was a scholar-athlete.

All-night terminal sessions are counterproductive.

The IBM 4250 printer has all-points-addressable graphics capabilities.

7.2 Use a hyphen between the components of any number (including fractions) below one hundred that is written as two words: thirty-five two-thirds

8. Apostrophes

8.1 Use apostrophe, s ('s) to indicate singular possessive:

Users keep turning on to IBM's VM operating system.

8.2 Use s, apostrophe (s') to indicate plural possessive:

We found the missing tools in the boys' clubhouse.

8.3 Use apostrophe, s ('s) to form the plural of abbreviations with periods, lowercase letters used as nouns, and capital letters that would be confusing if s alone were added:

M.A.'s and Ph.D.'s x's and y's S's, A's, I's SOS's

8.4 When you can do it without creating confusion, use s alone to form the plural of letters, figures, words treated as words, and hyphenated coinages used as nouns:

three Rs four 8sthey came in twos the 1980s a dozen ifs

9. Italics

9.1 Use italics (sparingly) to emphasize a word or phrase:

The GET command inserts data from the current line forward, so the user must be sure to make the appropriate line the current line before entering this command.

9.2 Use italics to identify a letter treated as a letter or a word treated as a word:

The word eyes appears twice in the first line of the poem.

9.3 Use italics to identify foreign words or phrases not yet absorbed into English.

10. Titles

10.1 Italicize (or underline) the titles of books, magazines, journals, newspapers, plays, operas, films, television shows, radio programs, and long poems.

10.2 Enclose in quotation marks the titles of short poems, essays, magazine articles, newspaper columns, short stories, songs, speeches, and chapters of books.

In journalism, see the following entries in the Associated Press Stylebook: "composition titles," "magazine names," "newspaper names." In summary, these entries indicate that most composition titles (books, plays, songs, television shows, etc.) should be enclosed in quotation marks but not in italics. Newspaper and magazine titles, however, should neither be italicized nor enclosed in quotation marks.

11. Numbers

11.1 Spell out a number when it begins a sentence.

11.2 Spell out a number that can be written in one or two words (except as noted in 11.3) and 11.5):

three twenty-two five thousand one million

11.3 If numbers that can be written as one or two words cluster closely together in the sentence, use numerals instead:

The ages of the members of the city council are 69, 64, 58, 54,47, 45, and 35.

11.4 Use numerals if spelling out a number would require more than two words:

3507,1254,978,2655.78

11.5 Use numerals for addresses, dates, exact times of day, exact sums of money, exact measurements (including miles per hour), game scores, mathematical ratios, and page numbers:

55 mph ratio of 4-to-1 $6.75 p. 37

In journalism, see the numerals entry in the Associated Press Stylebook.

12. Quotation Marks

12.1 Use double quotation marks to create irony by setting off words you don't take at face value:

The "debate" resulted in three cracked heads and two broken noses.

12.2 Do not use quotation marks to create emphasis (see 9.1).

12.3 Use single quotation marks to enclose a quotation within a quotation:

At the beginning of the>

12.4 If the quotation will take more than four lines on the page, use indentation instead of quotation marks to indicate that the passage is a quotation. Introduce the quotation with a colon, set it off from the rest of the text by triple-spacing (assuming the rest of the text is double-spaced), indent ten spaces from the left margin, and single-space the quoted passage. To indicate a new paragraph within the quoted material, indent an additional three spaces.

12.5 Do not use quotation marks with indirect discourse, or with rhetorical, unspoken, or imaginary questions:

Frank said he was sorry he couldn't be here.

Why am I doing this? she wondered.

13. Punctuating Quotations

13.1 Do not use a comma to mark the end of a quoted sentence that is followed by an identifying tag if the quoted sentence ends in a question mark or an exclamation point:

"Get out!" he screamed.

13.2 Commas and periods go inside closing quotation marks; semicolons and colons go outside the closing quotation marks:

Peter's response was "Money is no object," but the lawyer was still unwilling to accept his case.

The senator announced, "I will not seek reelection"; then he left the room.

13.3 Place a question mark or an exclamation point inside the closing quotation marks only if it belongs to the quotation rather than to the larger sentence:

Lenin's question was "What is to be done?" Should the U.S. support governments that it considers "moderately repressive"?

Wherever you use the question mark or exclamation point, do not use a period with it (see 18.1).

13.4 Use square brackets to enclose interpolations, corrections, or comments in a quoted passage. In journalism, use parentheses ( ) for this purpose.

14. Introducing Indented Quotations, Vertical Lists, and Formulas

The punctuation immediately following the introduction to an indented quotation, vertical list, or formula is determined by the grammatical structure of the introduction. Essentially, you should follow the same rules described in section 3 and section 1.2 even though the material you're introducing is set off from the rest of the sentence.

14.1 If the introduction is a main clause (a clause that could stand by itself as a complete sentence), follow it with a colon:

Each member of the expedition was asked to supply the following equipment:

 a sleeping bag

 a mess kit

 a propane stove

 a backpack

14.2 If the introductory element is not a main clause, follow it with a comma if one is required by the rule given in section 1.2:

According to Gene Fowler, "Writing is easy: all you do is sit staring at a blank sheet of paper until the drops of blood form on your forehead."

14.3 If the introduction is not a main clause and a comma is not required by the rule given in section 1.2, follow it with no punctuation at all:

In Philosophy and Physics, Werner Heisenberg points out that "The change in the concept of reality manifesting itself in quantum theory is not simply a continuation of the past; it seems to be a real break in the structure of modern science."

14.4 If you're uncomfortable with an unpunctuated introduction, try converting it into a main clause and using a colon:

In Philosophy and Physics, Werner Heisenberg makes the following observation about the effect of quantum theory on modern science:

15. Punctuating Vertical Lists

15.1 The items in an vertical list may be preceded by sequential numbers or bullets (usually dots or asterisks), or they may stand alone. Depending on their grammatical structure, the items are followed by periods, semicolons, commas, or no punctuation at all. The