Punctuation
For guidance on punctuation, consult the Chicago Manual or a grammar and usage book. Some common questions are answered by the following list.
ampersand
Use ampersands (&) only in charts, tables, or lists of companies, where the ampersand is part of the company’s official name. Use and in text.
brackets
Use brackets for parentheses within parentheses and for editorial interpolations or word substitutions in quotations.
“I took my first acting class at the age of 35 [which led to my] late start professionally.”
Use brackets to enclose editorial explanation.
According to Professor Lloyd, the bones date back to 250 B.C. [This date is currently in dispute; see interview with Dr. Margaret Thomas in the March 1992 issue of Time.]
Use brackets to set off phonetic transcripts of words.
The duiker [diy-kuh] is a small African antelope with an arched back and short horns separated by a long tuft of hair.
colon
If a colon introduces a complete sentence, more than one sentence, a formal statement, quotation, or speech in a dialogue, capitalize the first word of the sentence. If the colon introduces a sentence fragment, do not cap the first letter.
The class was informed of the house rule: Everyone, at every class session, must contribute to the general discussion.
The study covered three areas: nuclear waste, industrial waste, and cancer cases.
A colon commonly is used to introduce a series or list. The terms as follows or the following require a colon if followed directly by the illustrating or enumerated items or if the introducing clause is incomplete without those items:
- The steps are as follows:
- 1. Gather the ingredients …
- An outline of the procedure follows. The cooking times are based on temperatures of the lab oven. Times and temperatures may vary.
- 1. Gather the ingredients …
The colon is used when a sentence is intended to come almost to a dead stop:
Two things are essential to success: ambition and hard work.
However, when a sentence is not intended to be interrupted, a colon should NOT be inserted between a verb or preposition and its object:
Two things essential to success are [no colon] ambition and hard work.
A colon is used between the place of publication and the publisher’s name in bibliographical references:
Robert Pinsky, Landor’s Poetry (Chicago: University of Chicago Press, 1968), 95.
commas
compound sentences
Use a comma to separate parts of a compound sentence, placing the comma before the conjunction. Sentences with two verbs or verb clauses joined by and do not usually include a comma before the and. Use commas to set off a nonrestrictive or dependent clause (usually introduced by which). Do not use a comma with a restrictive clause (usually introduced by that, and usually the type of clause needed—which is often overused and incorrectly used).
Some of the people remained calm, but others seemed on the verge of panic.
We studied the properties of the quarks and then formulated several hypotheses.
The report, which had been completed in record time, was presented to the conference as scheduled.
The questionnaires that were distributed to female students had quite an impact on the survey results.
dates
Month, day, year:
June 13, 1971, was the day … ; On Tuesday, June 13, the University President presented his proposal.
Month and year only, no comma:
June 1976; December 1987; The meeting had taken place in August 1981.
Inc.
Use a comma before and after Inc. in text.
Jr., Sr., III
The latest edition of the Chicago Manual recommends that Jr., Sr., II, III, IV, etc., not be set off by commas unless the sentence structure dictates that a comma be used after.
The decision was left to Merriman Lyon Jr., Sung Soo Park, and Aruna Patel.
They named the twins JoEllyn Rachel Smith and Brian Carl Smith Jr.
Edward Muskakie III, professor of chemistry at Undine University, was scheduled to speak.
Queen Elizabeth II and the Prince and Princess of Wales were the guests of honor.
serial comma
Use a comma after the next-to-last item in a series.
The book compares the works of Cassatt, Degas, Morisot, and Monet.
Among her favorites were Dickens’s Bleak House, Little Dorrit, and A Tale of Two Cities.
state names in text
Use a comma before and after a state name when it’s used with a town or city name in text.
We were passing through Herkimer, New York, when we discovered that the tire was going flat.
street addresses in text
Use a comma at the end of a street address in text, if more copy follows.
Send inquiries to The Pennsylvania State University/859 Mitchell Building/University Park PA 16802, or to the Penn State campus nearest you.
ellipsis points ( … )
Avoid the use of ellipsis points if at all possible. They make the sentence harder to read and understand. Ellipsis points are appropriately used to indicate the omission of material from within a quotation, not as a way to “trail off” or pause. When ellipsis points are used within a sentence, use three. When ellipsis points are used between sentences, use four, the first or last of which serves as the period for the first sentence, depending upon where the omitted material occurs. Always use spaces between and around ellipsis points. (To typeset an ellipsis point on a Macintosh computer, hold down the option key and type a semicolon.) See the Chicago Manual for more detailed rules on the use of ellipsis points.
hyphens, dashes
(Also see the Hyphens section.)
A general rule is that hyphens link items and dashes separate items.
A hyphen joins words to form compound adjectives or is used to attach certain prefixes or suffixes to words.
The dash that is usually typed as two hyphens (--) is typeset as an em dash (—). It indicates a break in thought and can be used within a sentence to insert a parenthetical phrase. Macintosh users can insert their own em dashes by holding down the shift and option keys and typing a hyphen. Neither a double hyphen nor an em dash should have spaces on either side.
The en dash (–) is used between ranges of numbers or dates, or between adjectival phrases containing two-word concepts (on a typewriter, use a hyphen).
pp. 123–34
New York–Dallas flight
1984–87
but (in text):
from 1968 to 1972 (never from 1968–72)
between 1968 and 1970 (never between 1968–70)
To typeset an en dash on a Macintosh computer, hold down the option key and type a hyphen. En dashes do not have spaces on either side. Do not use an en dash to replace a hyphen.
If you need a detailed description, see the Chicago Manual.
lists
The easiest way to set off items listed vertically in a typed manuscript is to use em dashes. With sentence fragments in a series (vertical), it’s best not to use punctuation at the end of each line. However, if you do choose to punctuate for a special reason, be consistent with the punctuation marks.
- The agenda contained the following items:
- —plans for construction of recreation building
- —personnel decisions for the past month
If the listed items complete a sentence, use a semicolon after each item and a period after the last item. Do not place and before the last item.
- Ellen was interested in finding:
- —more space for the office;
- —more money for the staff;
- —more staff members.
If the items in a vertical list are complete sentences, cap the first word and put the appropriate punctuation at the end of each item.
- The commission refused to make exceptions to the following rules:
- —No brick shall be any color other than rusty red.
- —Each brick shall be placed adjacent to at least three,
- but not more than four, other bricks.
- —No broken brick shall be allowed to stand more than
- one day without being repaired.
If you decide to use numerals or letters with a list, use a period after them, not parentheses:
- 1. books
- 2. record albums
- a. the Korean War
- b. the Eisenhower administration
Numbers or letters enumerating items in a list within a paragraph should be enclosed in parentheses and should not be followed by a period:
He had, in effect, discovered remarkable similarities among (1) squirrels, (2) horses, and (3) hogs.
M.B.A./MBA
The degree is M.B.A., with periods, in all references. However, when referring to the program or to a person who has earned the degree, use MBA—no periods, no spaces. Plural: M.B.A.'s, MBAs.
Marisa Shala, B.S., M.B.A., will head the task force on improving MBA negotiating skills.
Two hundred MBAs attended the alumni workshop.
quotation marks
Quotation marks go inside semicolons and colons, outside commas and periods. Question marks and exclamation points go inside the quotation marks if they are part of the quote and outside if they are not. For more details, see the Chicago Manual.
- Did you watch “The Story of English”?
- Then he asked, “Did you check for magnesium in the sample?”
- Miller objected to the boss's reference to “nonessential personnel”: It made him feel unnecessary, as he was the only person in that category.
- The professors co-authored “Effects of Ultraviolet Rays on Plant Life,” published in the May 1986 issue of Science Today.
Items that should be in quotation marks: direct quotes; song titles; short poems; essays; television and radio programs; short story titles; article titles; parts of books (chapters or sections). For more complete information, see the Chicago Manual.
Reserve Officer Training Corps (ROTC)
Note no apostrophe; no periods with abbreviation.
semicolon
The following words are considered adverbs rather than conjunctions and should be preceded by a semicolon when used between clauses of a compound sentence: then, however, thus, hence, indeed, yet, so. Semicolons also are used to join complete sentences where a period would create too much of a pause in the train of thought:
I wanted to give you something special; I wanted to surprise you. I should be there at 5:00; however, traffic may prevent me from arriving any earlier than 7:00.
Veterans Administration (V.A.)
Use periods with this one.