Punctuation

Apostrophes

1. Use the apostrophe to:

   • indicate omitted letters in contractions: doesn’t, can’t, she’ll, they’re
   • show possession for nouns: a day’s rest, a professor’s grading scale, everyone’s campus, women’s rights

2. For singular words ending in the sibilant (s, x, z) sound, such as James or Moses, omit the final s to prevent an awkward repetition of sound:

   • James’ sweater
   • Moses’ tablets

3. For plural possessives ending in s, add the apostrophe at the end; for those not formed by s, add ’s:

   • musicians’ instruments
   • children’s programs
   • several groups’ issues

4. Use the apostrophe in the plurals of small letters; for capital letters used as words for letter grades, just add s to form the plural.
   Exception: To avoid confusion with the word as, use the apostrophe to designate the plural of the letter grade A.

   • Tennessee’s final two e’s make rhyming easy for country music lyricists.
   • All A’s will put you on the dean’s list, but Cs and Ds will disqualify you.

5. Form possessives of abbreviations as you would for spelled-out nouns. Singular possessive:

   • SAT’s standards
   • NAU’s teams
   • MLA’s guidelines

6. Use the apostrophe to indicate omission of the first two digits in a graduation year.

   • Dana Turner (SBS ’99)

7. Use the apostrophe in Presidents’ Day, but do not use the apostrophe in Veterans Day.

8. Do not use the apostrophe to form the plurals of figures, years, or abbreviations.

   • 1500s, 1960s, the late ’90s, CDs

9. Do not use the apostrophe for:

   • personal pronouns: I, we, you, he, she, it, they
   • possessive pronouns: my, our, ours, your, yours, his, hers, its, theirs
   • plural nouns that are not possessive: tomatoes, services, rooms

Colon

1. Use the colon as you would a semicolon between independent clauses when the second clause amplifies or illustrates the meaning of the first clause.

   • Chris managed her time wisely: she studied four hours daily after classes, exercised one hour each morning, and hiked or biked with friends on Sunday.

2. Only capitalize the first word following a colon when it begins the first of at least two complete sentences.

   • Al cited the reasons for conservation: Temperatures are rising. Polar ice caps are melting. Floods and droughts are increasing the outbreak of disease.

3. Use colons to introduce a series or a list that is preceded by a grammatically complete clause (see Vertical lists).

   • Watson wants to take three courses next semester: criminal justice, American history, and study skills.

4. Do not use unnecessary colons:

   • Correct: The popular courses are Programming Techniques, Feminist Justice, and Unity of Life I: Life of the Cell.
   • Incorrect: The popular courses are: Programming Techniques, Feminist Justice, and Unity of Life I: Life of the Cell.

Commas

1. Use the comma to separate independent clauses joined by a coordinating conjunction in compound sentences. Note the seven coordinating conjunctions: and, but, for, nor, or, so, and yet.

   • Carly was active in the American Democracy Project, and she credited that involvement with her success on Capitol Hill.

2. Do not use a comma between an independent clause and a dependent clause joined by a coordinating conjunction:

   • Correct: The sky is cloudy but bright.
   • Incorrect: The sky is cloudy, but bright.

3. Use a comma to set off nonrestrictive elements but not restrictive elements:

   • Nonrestrictive:
     Professor Short, who understands theory, responded appreciatively.
     Roget’s Thesaurus, too tattered to read, lay on the shelf.
     Mary Lou, Sam’s friend, graduated last spring.
   • Restrictive:
     Any professor who understands theory would respond appreciatively.
     An old book too tattered to read lay on the shelf.
     Sam’s friend Mary Lou graduated last spring.

4. Always use the oxford comma in a list of three or more items. If you incorporate multiple series in a sentence, use semicolons to separate the series:

   • Simple list: We have seen horses, tigers, and lions today.
   • Multiple series: NAU’s brand image has a standard color palette of blue, sage green, and gold; restrictions for use of the mark, typography, and signage; and conventions for layout of letterhead, envelopes, and business cards.

5. Use a comma after the city and state in the middle of a sentence.

   • Flagstaff, Arizona, sits at the foot of the San Francisco Peaks.

6. Use a comma following the day and year in a complete date, but omit the comma when citing only the month and year:

   • The concert took place on Tuesday, January 23, 2017, at Ardrey Auditorium.
   • We saw the beginning of a great ski season in November 2018.

7. Do not use a comma between last names and Jr., Sr., II, III, etc.

   • Jeffrey Mark Wiley Jr.

Dashes and hyphens

En dash

The en dash is the width of the letter n (–), about as wide as a hyphen and a half. The en dash is used to represent a span or range of numbers, dates, or time. In most cases, there should be no space between the en dash and the adjacent material. (See #5 for an exception.) Depending on the context, the en dash is read as “to” or “through.”

Use en dashes to do the following:

1. Connect numbers and, occasionally, words:

   • Her years at NAU, 1999–2003, were the most inspiring she’d experienced.
   • See the text on pp. 82–92.
   • The sessions meet weekdays, 9:30–10:45 a.m.
   • The Flagstaff–Phoenix shuttle leaves four times daily.

2. Indicate an ongoing activity:

   • The research on Pluto (2005– ) will determine if it is indeed a tailless comet.

3. The following NAU campuses have an en dash with no spaces on either side¹:

   • NAU–Yuma
   • NAU–North Valley
   • NAU–Yavapai
   • NAU–Yavapai Prescott Valley Campus

4. Creating an en dash in Microsoft Word:

   • PC: To form the en dash in Microsoft Word, type a word or number; then space, hyphen, space; followed by a word or number. When you type the following space, Word will auto-convert the dash to an en dash.
   • Mac: Simultaneously hold down the Option button and the dash button.

5. For degrees, use a space between the en dash and the degree and the emphasis.

   • Francisco Santa Cruz, Strategic Communication – Advertising and Public Relations major with a minor in Mathematics

Em dash

The em dash is as wide as the letter m—about twice as wide as a hyphen.

Use em dashes to do the following:

1. Set off explanatory elements:

   • Every student—resident, commuter, online—must fulfill the same requirements.
   • The president—a lifelong history scholar—cited the differences between Jefferson and Adams.
   • She studied a variety of topics about the region—language, culture, geology—before visiting Chile.

2. Show sudden breaks:

   • The jewelry—she couldn’t possibly have left it at the transit shelter—was made by her Navajo ancestor more than two centuries ago.

3. Creating an em dash in Microsoft Word:

   • PC: To form the em dash in Microsoft Word, type a word; then space, two hyphens, space; followed by a word. When you type the following space, Word will auto-convert the dash to an em dash.
   • Mac: Simultaneously hold down the Option and Shift buttons and the dash button.

Hyphen

The hyphen connects or divides words and word elements:

1. Hyphenate compounds that function together as adjectives:
   Note: Do not use a hyphen after words ending in -ly: highly dedicated professors.

   • third-century literature
   • quasi-impressionistic art

2. Hyphenate a compound with the prefix well before the noun:

   • The well-known athletes train here.
   • The athletes who train here are well known.

3. Hyphenate temporary compounds:
   Note: Consult a current dictionary or style manual to verify compound words.

   • anti-intellectual
   • off-the-wall
   • post-homecoming

4. Use the hyphen to separate number and word constructions:

   • 312-555-5555
   • non-English-speaking countries
   • poverty-stricken hurricane victims

5. Use the hyphen to divide words at line-ends. If the line has space for one or more syllables but not for the whole word, use the hyphen to divide the word between syllables. If you are not certain where one syllable ends and the next begins, refer to your dictionary.

Ellipses

1. Use three points (an ellipsis), with no space before and after, to indicate text omitted within a sentence. When writing for web, please use the appropriate HTML codes or keyboard shortcuts for a properly formatted ellipsis (…).

   • He said that she “will continue the lecture series…when she returns from sabbatical.”

2. To indicate omitted material after the end of a sentence, use the period plus three points.

   • “Laura admired the entire program.…Her research showed none like it in the nation.”

3. Generally, do not use an ellipsis at the beginning or end of quoted material unless you wish to emphasize that the quote is partial.

Exclamation point

Exclamation points are never allowed on nau.edu webpages. Use sparingly to show strong emotion, surprise, or disbelief on print materials.

Parentheses

If a dependent clause or phrase is in parentheses, put final punctuation outside the final parenthesis. If the parentheses enclose an entire sentence, put final punctuation inside the closing parenthesis:

• Joni enrolled in the class, thinking the assignments would be easy (but she was wrong).
• Mary advised her student to study in the Grand Canyon. (She scoffed at the notion that the activity would be too rigorous.)

Periods

1. Use the period to end declarative—and some imperative—sentences:

   • Declarative: We all need to prioritize our tasks.
   • Imperative: Prioritize your tasks.

2. Use the period after some abbreviations (see Abbreviations).

3. Headlines/subheads: Don’t end with a period. If the headline is a full sentence, it may look odd to leave out the period. University Marketing may approve exceptions based on the layout of the piece. See the capitalization page for how to capitalize a header and subheads. 

Quotation marks

1. Place quotation marks outside of commas and periods but inside of semicolons and colons.

   • “When I move to Arizona,” David told me, “I’ll buy good hiking boots.”
   • The guide shouted out the age of the rock strata lining the canyon: “Precambrian, Paleozoic, Cenozoic”; however, the roar of the rapids drowned his words.

2. Place question marks and exclamation points inside quotation marks if the quote is a question or outside if not.

   • Did you read Hemingway’s short story “The Short Happy Life of Francis McComber”?
   • She asks this question every semester: “How does the punctuation change the meaning of the title?”
   • While scanning the list, he blurted out, “Look at the amount of reading required for this class!”
   • She asked, “Does the syllabus include ‘Young Goodman Brown’?”

3. Use quotation marks to enclose titles of short stories, articles, poems, individual book chapters, songs and other short musical compositions, and radio and television shows.

4. Italicize titles of books, paintings, sculptures, films, magazines, plays, CDs or albums, operas and other complete musical works, newspapers, and continuing radio and television shows.

5. Quotations within quotes:

   • In running text, nest single quotes inside double quotes.
   • In block quote formats (e.g., Q&A pages) that do not normally use quotation marks, use double quotes.
   • Examples:
     • “Don’t be absurd!” said Henry. “To say that ‘I mean what I say’ is the same as ‘I say what I mean’ is to be as confused as Alice at the Mad Hatter’s tea party.”
     • Don’t be absurd! To say that “I mean what I say” is the same as “I say what I mean” is to be as confused as Alice at the Mad Hatter’s tea party. – Henry

Semicolon

1. Use the semicolon between closely connected independent clauses that are not joined by one of the seven coordinating conjunctions (and, but, for, or, nor, so, yet):

   • Each semester she receives excellent evaluations from peers; chief among those high marks is her success in raising awareness about the issues.
   • The professor’s instructions were clear; however, the students’ responses were not. (Note the use of the subordinating conjunction, however.)

2. Use the semicolon to separate elements that incorporate internal commas.

   • The course requires books on geography, geology, and paleontology; and field trips to mountains, plateaus, and canyons.

Slash

1. The slash (/), also known as the virgule, has several uses, most of which should be avoided in formal writing. Never use a backslash (\) in place of a slash.

2. The slash can serve as shorthand for per, and, or in informal writing.

3. Use the slash when writing about NAU’s 90/30 degree program. The catalog will not accept 90/30, so you may often see 90-30:

   • Correct: 90/30
   • Incorrect: 90-30

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1. Note: Other partner campuses that don’t have NAU in the title use the same style when their location needs to be included. For example, Pima–West. NAU–Yuma is an ABOR-designated branch campus, while the others are partner campuses (such as community colleges) or NAU statewide campuses. To describe any or all of this whole group, statewide locations or statewide campuses are both acceptable. Use the branch campus designation or community college only if it is helpful in distinguishing the location and/or making your point. For example, the branch campus at Yuma may express our commitment to Yuma or an elevated status. Distinguishing the community college sites may help to explain a transfer program. Statewide campuses can change so always consult the latest list. Location names are subject to change, so best practice is to verify.↩︎