There is no alternative to correct punctuation. Incorrect punctuation can change the meaning of a sentence with the result being an ill-informed reader. Even if the meaning of a sentence is not altered by poor punctuation, it can cause a reader to lose track of what is being said, leading to confusion.


“It’s” vs. “Its,” “Its” vs. “Their,” and Other Possessives
If you are talking about a contraction of the phrase “it is,” use “it’s.”
If you are talking about a possessive situation—“the thing belonging to it”—use “its.”

“It’s no secret that the university encourages diversity.”

Use “it” and “its” when referring to possessive situations involving groups, schools, corporations, etc.; they are entities. Do not use “their.”

The College of Science has increased the number of its (not “their”) faculty.
Xerox follows the progress of its (not “their”) co-op students carefully.

Singular possessives and plural possessives confuse a lot of folks. Here are some examples of words in singular possessive, plural, and plural possessive forms.

Possessive Plural Plural Possessive
child's toy children children's toy
boy's hats boys boys' hats
Phyllis's home the Phyllises the Phyllises' home
Santa's nose many Santas many Santas' noses
its own their own their own


Never, absolutely never, use apostrophes to pluralize (“raining cat’s and dog’s,” etc.). Not even for proper names ending in “s.” In that case, either end the name in “es” or leave it singular as appropriate to the name; usually it’s “es.” (“The Myerses say they love teaching.”) For acronyms, don’t use an apostrophe unless the acronym ends in “S.” (CODs, IOUs, but MS’s, BS’s). When in doubt, consult the Associated Press Stylebook.


Use commas or semicolons to separate items in a series. Which to use? Here’s how to tell: If you have a series of three or more elements that are simple and similar, use commas.

apples, peaches, and pumpkin pie
Joe Smith, Mary Jones, and Susan Stacy received scholarships.

If you are listing many different elements to describe something, and the descriptions are wordy (especially if they also contain internal commas), separate with semicolons.

He is a 2016 graduate of RIT; a renowned illustrator for Vanity Fair, The New Yorker, and The Atlantic; and a talented tenor.

If you need to set off individual elements in a long list (such as a series of students’ names and their colleges), use a combination of the two, with a comma following the last item in the series.

Joe Smith, College of Science; Mary Jones, NTID; and Susan Stacy, College of Engineering, received scholarships.

Use an internal comma after the date and year when a specific date is given. Do not use internal commas when a specific date is not given.

On Sept. 28, 2016, we went to Toronto.
In September 2016 we went on vacation.
At 3 p.m., Sept. 28, we will hold a meeting.

Also use commas to separate the elements in addresses and places:

Colleen Clarke is originally from Ithaca, N.Y., but now lives in Hilton.

And use them to set off appositive (nonrestrictive) clauses:

Jim Miller, senior vice president of Enrollment Management, came to RIT from Eisenhower College.

Ditto for appositive words:

Neil’s wife, Barbara, is a teacher. (Her name is not essential; Neil has only one wife, so the reader knows who is the teacher.)

But restrictive words and phrases do not use commas:

Karen’s son Scott is excited about the Lions this year. (There could be more than one son, and the name is necessary to identify which one is a Lions fan.)

Use commas between the clauses in a compound sentence unless they are very short and closely related. Do not use commas with a compound predicate.

The client asked if the job could be delivered the next day, and the printer jumped out the window.
The student studied all night and took the test in the morning.

Use a comma before “including” and “such as” when followed by a nonrestrictive, nonessential phrase or clause.

The new policy applies to everyone, including faculty.
Some students make silly excuses, such as “My dog ate my homework.”

Do not use a comma when using a phrase like “as well as,” in which the clause is essential and restrictive.

The new policy applies to faculty as well as staff.

Do not use commas after a man’s name if he is a “Jr.,” “Sr.” “II,” “III,” etc.

Wrong: Dr. Martin Luther King, Jr.
Right: Dr. Martin Luther King Jr.

Wrong: The Mod Squad featured Clarence Williams, III.
Right: The Mod Squad featured Clarence Williams III.


Em Dashes (Double Hyphens or Long Dashes)
These often are used to expand or highlight a part of a sentence that appears to be a break in thought or to introduce a clause or insert.

“What you or I need is the right word—fat or thin, brisk or lazy.” Willard Espy

En Dashes
Use the en dash, not the hyphen, for events that continue for a given length of time in calendar listings. In text, use the words “from” and “to.”

Hyphens are used to separate parts of a compound adjective, except those with an “-ly” ending. (Refer to the Chicago Manual of Style for the use of hyphenations with “-ly” endings.)

The course is for hard-of-hearing students. But He is hard of hearing.
It was a shoot-em-up Western.
Frank Lloyd Wright was a highly regarded architect.

In suspended compounds, hyphens serve as placeholders for the omitted part of the compound:

The course is for full- and part-time students.
CIMS assists small- and medium-sized manufacturers.

Dont hyphenate compound adjectives when they appear after or apart from the noun they modify or are used as adverbs:

part-time student Julie Jackson
Julie attends RIT part time
Frank Lloyd Wright, the well-known architect
well known as an architect

In words beginning with “co,” retain the hyphen when forming nouns, adjectives, and verbs that indicate occupation or status: co-author, co-chairman, co-owner, co-partner. Use no hyphen in other combinations: coed, coeducation, coequal, coexist, cooperate, cooperative, coordinate. But use co-op.

Do not hyphenate Student Alumni Union.

For telephone numbers, use hyphens between sections of the number. Do not use parentheses around the area codes. The form is 212-621-1500. For international numbers use 011 (from the United States), the country code, the city code, and the telephone number: 011-44-20-7535-1515. The form for toll-free numbers is 800-111-1000. If extension numbers are needed, use a comma to separate the main number from the extension: 212-621-1500, ext. 2.


Use a single space after a period at the end of a sentence.

Dont use periods at the end of incomplete sentences or lists:

Courses include:
•  Microelectronic Feats
•  Hydroelectricity and Sound
•  Transformer Conversions

Use an ellipsis (…) to indicate omitted words within a sentence or quote. In general, treat an ellipsis as a three-letter word, constructed with three periods and two spaces (that is, leave one regular space on both sides of an ellipsis).

“I’m sure the after effects will ... be with people for a while,” he said.

If the words that precede an ellipsis constitute a grammatically complete sentence in the original (or if quote is condensed), place a period at the end of the last word before the ellipsis. Follow it with a regular space and an ellipsis:

Abraham Lincolns Gettysburg Address speaks of the need to preserve
“... government of the people, by the people and for the people. ...”

Quotation Marks and Italics

Use quotation marks for titles of articles; chapters in books; academic papers; radio and TV programs that are not part of a regularly scheduled series; songs; seminars for which the name is descriptive; and workshops. Also use them for comments made by interviewed people, of course.

She thought “The MTV Video Music Awards” wasn’t as good this year as last.
Snow White sang “Someday My Prince Will Come.”
Don’t you want to go to the “Learning the Internet” seminar?
They hadn’t heard of the “Getting Along with Your Adult Kids” workshop.

Remember to put single quotes inside double quotes when quoting a person quoting someone else or quoting a title of the above:

"Everyone in Belgrade is singing ‘We Live Again,’” he reported.
“My article, The Reproductive Cycle of Female Brown Shrimp in the North Sea,’ will be published soon,” she said.

Use italics (not underlines) for titles of books, magazines, newspapers, TV series, plays, and movies.

Titanic was as over-rated as the ship itself but stayed afloat nevertheless.
Al Pacino was featured in The Insider.
He wants to be published in The New York Times.
Everyone knows that appearing on the cover of Sports Illustrated is a jinx.
The line was so long, I could have finished reading War and Peace before I got service.

Punctuation should always appear inside quotation marks, except when using semicolons and colons, and in the case of question marks and exclamation points that apply to the entire sentence, not just the quoted material:

Have you heard the song “Steamroller”?
“I can’t believe they actually sang ‘Why Don’t We Do It in the Road?’!”


When URLs must be broken at the end of a line of type, break the URL at a slash.