Sign Up Log In

DictionaryThesaurusWord DynamoQuotesReferenceTranslatorSpanish

Punctuation

Dictionary.com » Style Guide » Punctuation

Ampersand (&)

• The ampersand is used when it is part of a formal name, as for a company, e.g. Baltimore & Ohio Railroad. It should not be used in place of 'and' except in extremely informal writing. No spaces are used with an ampersand used within an initialism, e.g., R&D, but are used within the name of a company, e.g., Ginn & Co.

Apostrophe ( ' )

See Possessives for more information.

• The apostrophe is used when leaving out a letter or number in a contraction, e.g. can't, wouldn't.
• The apostrophe is used for omitted letters, e.g. rock 'n' roll, and for omitted numbers, e.g. the class of '72, the '20s.
• The apostrophe is used for plurals of letter abbreviations with periods and single letters, e.g. p's and q's, two A's and four B's. Plurals of multi-letter combinations and plurals of numerals end in s with no apostrophe, e.g. VIPs, 1000s. However, in order to avoid confusion, lowercase letters and abbreviations with two or more interior periods, or with both capital and lower case letters form the plural with an apostrophe and an s: x's and y's; M.A.'s and Ph.D.'s (or MAs and PhDs).
• The possessive of singular nouns ending in s, including nouns ending in s, x, z, ch, or sh, is formed by adding 's, e.g. witness's affidavit. However, if the next word begins with s, then add only an apostrophe, e.g. witness' story.
• The possessive of singular nouns not ending in s is formed by adding 's, e.g. VIP's seat, baby's food.
• The apostrophe follows the s of a word with two sibilant sounds, e.g. Kansas', Moses'.
• The apostrophe is added for the possessive of a noun that is plural in form but singular in meaning, e.g. mathematics' formulas.
• The apostrophe follows the s for the possessive of plural nouns that end in s, e.g. girls' movies. For the possessive of a plural noun that does not end in s, add 's, e.g. women's rights.
• For singular proper nouns, add only an apostrophe for the possessive, e.g. Achilles' heel.
• No apostrophe is used for personal pronouns like hers, his, its, mine, ours, theirs, whose, your, yours. Indefinite pronouns require an apostrophe, e.g. one's lover. For other pronouns like another and others, follow the rule for singular and plural, e.g. another's and others'.
• For joint possession, the 's is added to the word nearest the object of possession, e.g. Francis and Kucera's book.
• The apostrophe is not used in names of organizations unless actually part of the legal name. The apostrophe is not used in plurals of numerals or multiple-letter combinations.

Brace ({ })

• Punctuation used to show the relationship of elements in a group.

Bracket ([ ])

• Punctuation used to insert words in quoted matter for explanatory, correctional, or commentary reasons. Brackets are used to insert missing letters and to enclose insertions that take the place of or slightly alter the original text, e.g. [they] may replace a long list of names previously mentioned. Brackets are also used in unquoted matter for the same reasons.
• Brackets are used as parentheses within parentheses, e.g. (In an article published in theTimes [December 2, 1991], he was quoted as saying that the company was flourishing.)
• Brackets are used in mathematical expressions to show matter to be treated as a unit. Brackets are used for chemical formulas and to enclose phonetic symbols.

Colon (:)

• Punctuation used to introduce explanatory information such as tabulations, lists, etc.; for salutations, as 'Dear so-and-so'; in clock time (e.g. 2:15); for periodical reference (e.g. 4:3); and between book title and book subtitle (e.g. Dictionaries: The Art and Craft of Lexicography).
• A colon is used before a final clause that explains or amplifies something in that sentence, e.g. The dissertation needs work: it lacks flow.
• A colon introduces a series or summarizing statement, e.g. The following is on our list of places to go: grocery store, toy store, doughnut shop., She had one great love: him.
• A colon is used in proportions, e.g. 2:1, and as a ratio sign, e.g. 1:2::3:6.
• A colon may introduce a quotation, especially a long one. Colons go outside quotation marks unless they are part of the quotation itself. A colon also is used to end all paragraphs that introduce a paragraph of quoted material.
• A colon is used in dialogue text, e.g. Kyle: Do you want to have lunch? Holly: Yes.
• A colon is used in correspondence for headings and introductory terms, e.g. To:, From:, Re: and to separate writer/typist and carbon-copy abbreviations from the recipients.
• A colon can give emphasis, e.g. He had only one hobby: eating.
• Capitalize the first word after a colon only if it is a proper noun or starts a complete sentence, e.g. Scientists have found a name for the opposite of gravity: levity. The panel consists of: Dr. Juli, Dr. Kipfer, and Dr. Bellantoni.
• Do not combine a dash and a colon.

Comma ( ,)

Punctuation most commonly used to separate or set off items as:

• Separate items that might otherwise be misunderstood, e.g. What the problem is, is not clear.
• Separate members of a series used with 'and', 'or', or 'nor', e.g. The flag is red, white, and blue.
• Separate main clauses or before the conjunction in a compound sentence, e.g. Either you start doing more work, or you will have to look for a new job. She was glad she had looked before backing out, for a child just whizzed by on the sidewalk.
• Separate two verb phrases in a sentence, e.g. She did earn a Master's, but now she is going to go on and earn a Ph.D.
• Set off subordinate clauses/phrases within sentence, e.g. On the street, the partygoers gathered for the fireworks.
• Set off an apposite (noun referring to previous noun, e.g. my sister, Nancy) or contrasting words/phrases (e.g. I need you, not anyone else.).
• Set off introductory items, clauses, or phrases, e.g. "Sir, are you listening?".
• Set off interrupting or parenthetic items, e.g. He has no reason, does he, to want to play basketball for that coach?
• Before a quotation following an introductory phrase, e.g. "She said quietly, "I love you." Inside a closing quotation mark, e.g. I said "wash," not "drawer." Commas always go inside quotation marks in American English usage.
• To show omission of a verb or predicate, e.g. Brad Pitt once worked as a giant chicken; Rod Stewart, as a gravedigger; Whoopi Goldberg, as a makeup artist in a mortuary.
• Between compound qualifiers / equal adjectives, e.g. He has big, broad shoulders.
• Between name and title, title and organization, name and degree, surname and Junior/Jr./Senior/Sr. In an inverted name, e.g. Kipfer, Barbara Ann.
• To separate thousands, millions, etc. in numbers of four or more digits, e.g. 2,000.
• To set off the day of the month, e.g. They got together on June 1, 1991, for the first time. To set off elements of an address, e.g. Write to him at The Language Centre, University of Exeter, Exeter, England EX4 4QH.
• After the salutation in informal correspondence, e.g. Dear T.B., and after the complimentary close in all correspondence, e.g. Respectfully,.
• To separate states and nations used with city names, e.g. LaPorte, Indiana.
• To set off yes and no, e.g. No, I will not be there.

Dash ( - )

Punctuation used to denote a sudden change or break in a sentence, e.g. He was gone -- heaven forbid -- for an hour and no one knew where he was. Spaces may or may not be added before or after a dash, but the use of spaces must be consistent. Do not combine a dash with a colon, comma, or semicolon. Other common uses:

• As a substitute for parentheses or commas in an attempt to clarify meaning or place emphasis, especially for a series within a phrase, e.g. She has this to accomplish today -- work, study, cook, and household duties -- as well as take care of her child.
• Before an amplification, definition, explanation, or summary statement, e.g. To be or not to be -- that is a question we each ask ourselves at night before we turn out the light.
• At the end of an unfinished word or sentence, e.g. The story went on to say that--.
• To precede an author's credit for a quotation, e.g. "As a cure for worrying, work is better than whiskey." -- Thomas A. Edison
• As a way of setting off something in page design, as for lists, outlines.
• The en dash is used in typeset material and is shorter than the em dash, which is represented in typewritten material by two hyphens. The en dash is used as a replacement for a hyphen when the meaning intended is 'up to and including', e.g. 1987-91, Monday-Saturday.
• A two-em (four-hyphen) dash is used to show missing letters in a word.
• A three-em (six-hyphen) dash is used to show that a word is left out or that an unknown word or number is to be supplied.
• To introduce individual sections of a list. Capitalize the first word following the dash and use periods at the end of each section.

Division of Words

Guidelines for dividing words at the end of lines are:

• Pay attention to the way the word is pronounced - its syllables -- and do not break the word so that it would be mispronounced or misunderstood. Check a dictionary if you are unsure of the syllable breaks.
• Divide between doubled consonants, except when it would divide a simple base form, e.g. re-com-men-da-tion, but sell-ing, buzz-er.
• Do not divide a one-syllable word, even if there is an inflected ending like '-ed', e.g. spelled, bummed.
• Do not divide a word so that one or two letters is left either at the end of one line or the beginning of another. Division after a prefix of three or more letters is permissible.
• Do not divide words of six letters or less.
• Divided hyphenated words at the hyphen.
• Do not divide before the following suffixes; they should not be at the beginning of a line alone nor should they be divided themselves: -able, -ceous, -cial, -cion, -cious, -geous, -gion, -gious, -ible, -sial, -sion, -tial, -tion, -tious.
• When a vowel alone forms a syllable in the middle of a word, keep it with the previous syllable, e.g. physi-cal.
• A liquid or silent 'l' syllable at the end of a word or part of an inflected ending should not be put on the next line alone, e.g. read-able, twin-kling.
• Proper nouns, contractions, initialisms, numerals, and abbreviations should not be divided.
• Do not leave a syllable at the end of a line that might be read as a complete word.
• Please note that both the MLA and APA style manuals now discourage breaking words at the end of lines. If you are using a computer, the word-wrap feature will eliminate most end-of-line divisions. Some word processing programs offer automatic hyphenation.

Ellipsis Points or Ellipses or Points of Ellipsis or Suspension Points ( ... )

• Punctuation used when words are omitted: three periods in the middle of a sentence, four at the end of a sentence (unless the sentence ends with a question mark or exclamation point: then it is ...? or ...!). Ellipsis points may also indicate a break or suspension in speech, e.g. I ...tried to do what was best. Punctuation that normally falls before or after the ellipsis points can be retained for clarity. A space precedes and follows ellipses except when the ellipsis is next to other punctuation.

Exclamation Point (!)

• Punctuation used to show surprise, incredulity, and other emphatic expressions, as well as praise or a command, e.g. Excellent! An exclamation point may be used to replace a question mark when irony or an emphatic tone is meant, e.g. How could you! An exclamation point and question mark may be used together to show extreme force, e.g. "Never!" If the exclamation point ends a sentence in a quotation, the comma or period is dropped. An exclamation point is inside quotation marks when it is part of the quoted material.

Hyphen (-)

Punctuation used:

• to connect the elements of some compound words, especially ones of three or more words, e.g. get-together, up-to-date
• to divide syllables of a word at the end of a line
• in fractions and compound numbers, e.g. fifty-five, twenty-one
• in measurements with numbers and unit, e.g. twenty-five dollars
• in ages with number and unit, e.g. forty-nine years old
• to make a word clear from its homonym, e.g. recover and re-cover
• in prefixed or suffixed words when a vowel is doubled or consonant is tripled, e.g. shell-like
• for certain prefixes, as ex-, e.g. ex-husband
• for certain suffixes, as -elect, e.g. president-elect
• for compounds which begin with a single capital letter, e.g. H-bomb, U-turn
• for compound modifiers preceding a noun, e.g. full-time job, except for the adverb 'very' and all adverbs that end in -ly
• for compound adjectives where the first adjective ends in -ly, e.g. 'scholarly-written piece'
• for directions, e.g. north-northwest
• for words spelled out letter-by-letter, e.g. y-e-s
• to show stuttering speech
• to avoid ambiguity which would result if the hyphen were omitted
• for two-thought compounds, e.g. serio-comic, socio-economic
• for compound proper nouns and adjectives, e.g. Mexican-American (but not for French Canadian or Latin American). Proper nouns and adjectives, hyphenated: Franco-Prussian War, Anglo-American cooperation, the Scotch-Irish (hyphenated in both noun and adjective forms. Proper nouns and adjectives, open: African Americans, an African American, a Chinese American child, French Canadians, etc. Whether terms such as African American, Italian American, Chinese American, and the like should be spelled open or hyphenated has been the subject of considerable controversy, the hyphen being regarded by some as suggestive of bias. Chicago doubts that hyphenation represents bias, but since the hyphen does not aid comprehension in such terms as those mentioned above, it may be omitted unless the write prefers it.
• for suspensive hyphenation, e.g. 10- to 20-year prison sentence

Numerals/Numbers

Roman numerals use the letters I (1), II (2), III (3), IV (4), V (5), VI (6), VII (7), VIII (8), IX (9), X (10), L (50), C (100), D (500), M (1000). They are used to number wars, show sequence in family, rulers, and vehicles; and for major headings in documents and outlines. Arabic/cardinal numbers are 0, zero, 1, one, etc. Ordinal numbers are 1st, first, 2nd, second, etc.

• In general, write out the first nine cardinal (1-9) numbers (except for address numbers 2-9, dates, decimals, game scores, highways, latitude/longitude, mathematical expressions, measurement/weight, money/financial data, percentages, proportion, scientific expressions, statistics, technical expressions, temperature, time, unit modifiers, votes, and numbers not written out in a proper noun) and any number that begins a sentence. Use figures for the number 10 and above.
• The first nine ordinal (1st-9th) numbers are usually written out, especially when describing order in time or location.
• Governmental, political, and military units numbered one hundred or less are usually written out. Labor unions and other organizations often use figures.
• Numbers of one million and above are easier to read if written as figures with the word 'million', 'billion', etc.
• Written-out numbers between 21 and 99 are hyphenated. Higher numbers are not hyphenated, e.g. three hundred.
• Figures of four digits may be written with or without a comma.
• Numbers of checks, contracts, military hours, pages, policies, rooms/suites, streets, telephone numbers, and years are written without commas. Check, telephone, credit card, and serial numbers may contain hyphens.
• A fraction used as a modifier is hyphenated, e.g. three-quarter time.
• A fraction used with a whole number is written as a figure, e.g. 5 3/4, as are measurements that are fractions, e.g. 1/2 mile.
• A measurement as a modifier is hyphenated, e.g. nine-pound boy.
• Numbers in a series or set are written alike, e.g. 50 to 60 participants.
• Street names that are numbers are written out, but may also be written as figures from 13 and over, e.g. 300 Third Street, 300 13th Street or 300 Thirteenth Street.
• Document divisions are usually written as figures, e.g. Psalm 100, page 7.
• Ordinal numbers are not used in full dates, e.g. March 12, 2003. Commas are rarely used in between just a month and year, e.g. March 2003.
• Money designations of one or two words are often written out, e.g. one dollar.
• Times are usually spelled out in text and may be when used with 'o'clock'. Figures are used for exact times, e.g. 8:13. Times may be used with a.m./A.M., p.m./P.M., 'o'clock', or 'in the '.
• Year and page numbers may omit hundreds and replace with a dash, e.g. 1989-90, pp 140-50.
• If an abbreviation or symbol is used with a number, it should be written as a figure, e.g. p. 14.
• Numbers should not be divided at the end of lines.
• Plurals of written-out numbers are formed by adding s or es, e.g. nines, sixes.
• Plurals of figures are formed by adding s, e.g. 600s, 3s.

Parentheses ( )

Punctuation to enclose supplementary matter that is not intended to be part of the statement. At the end of a sentence, the period follows the closing parenthesis. A complete sentence within parentheses has its own punctuation - but if it qualifies as a sentence but is dependent on the surrounding material, do not capitalize the first word or end with a period. Parentheses may indicate something important, but their use is interruptive. Uses include:

• Numeric data, including Arabic numerals confirming a spelled-out number, and for other mathematical expressions.
• Explanation, definitions, translations, alternatives.
• Abbreviation of the spelled-out word or vice versa, the spelled-out form of an abbreviation.
• Bibliographical data and text references.
• Cross-references.
• Comments about a text.
• Numbers or letters indicating an item in a series are enclosed as, (1), (2), (3) and (a), (b), (c). Alternatively, one may use a right parenthesis [ ) ], e.g. We need: 1) a decision on the chapter names, 2) overall approval of the proposal, and 3) agreement on who the authors will be.

Period (.)

Periods always go inside quotation marks in American English usage. This punctuation is used:

• At the end of a declarative sentence, at the end of a mildly imperative sentence; at the end of a rhetorical question and any other question that is a suggestion and is not requiring an answer (indirect questions).
• After a letter or number indicating an item in a series.
• As part of an ellipsis.
• In numbers with integers and decimals.
• In many abbreviations.
• After a person's initials.
• Centered, to indicate a multiplication sign, as 2 ⋅ 3 = 6.

Possessives

The possessive case of most nouns is formed by adding an apostrophe or an apostrophe and 's'.

• Possessive for singular and plurals nouns not ending in an S or Z sound are formed by adding 's. Examples: horse's, alumni's
• Possessive of singular nouns ending in an S or Z sound are usually formed by adding 's, e.g. hostess's, unless the next word begins with an S or Z sound.
• Possessive of plural nouns ending in an S or Z sound are formed by adding only an apostrophe, e.g. churches'.
• Possessive of plural nouns that are singular in meaning are formed by adding only an apostrophe, e.g. mathematics' rules. This is also true for a plural word in the formal name of a singular entity, e.g. General Motors' profits.
• Possessive for noun that is the same in singular and plural - is formed as if it is plural, e.g. two deer's tracks, one corps' mess hall.
• Possessive for singular proper noun ending in s - use only an apostrophe, e.g. Achilles' heel.
• Possessive for pronouns -- only for a few, such as: another's, others', someone's. There are no separate forms for the possessive for: mine, ours, your, yours, his, hers, its, theirs, whose.
• In a phrase: individual possession is shown with an 's added to each noun, e.g. 'Barbara's and Kyle's bicycles'; joint possession is shown by adding an apostrophe or 's to the last noun in the series, e.g. 'Barbara and Kyle's house'.
• Be careful of descriptive phrases. Do not add an apostrophe to a word ending in 's' when it is used primarily in a descriptive sense, e.g. citizens band radio, writers guide.
• An inanimate object can have a possessive use. It is treated in a personified sense, e.g. Time's cover.

Question Mark (?)

Punctuation after a direct interrogatory statement and one expressing doubt. It is used after each element of an interrogative series when the series is not enumerated or lettered.

• Do not put a comma after a question mark that falls within quotation marks.
• Do not use question marks to indicate the end of indirect questions.

Quotation Marks (Double) (" ")

Punctuation that most often includes a period or comma. A dash, semicolon, question mark, or exclamation point fall inside quotation marks if they apply to the quoted matter only. A dash, semicolon, question mark, or exclamation point go outside when they apply to the whole sentence. Quotation marks are used:

• For direct quotations. Each part of an interrupted quotation begins and ends with quotation marks, as "I am getting worried," she said, "that he has not called."
• For quotations which extend beyond one paragraph, a quotation mark begins each paragraph and the closing quotation mark is at the end of the last paragraph.
• For expressions following introductory terms such as 'entitled', 'the word', 'the term', 'marked', 'designated', 'classified', 'named', 'endorsed', 'cited as', 'referred to as', 'signed' - which indicate a borrowing, special use, or definition.
• Around mottos, slang, nicknames, misnomers, coined words, unfamiliar terms, proverbs and maxims, ironical reference, and unspoken dialogue.
• Around words referred to as words, e.g. "I said "tomato," not "potato.", and around sentences referred to as sentences, e.g. An example of a question is, "Where the heck are they?". Single quotation marks may also be used in this way.
• For translations/definitions of foreign terms, e.g. E pluribus unum means "Out of many, one."
• For single letters within a sentence, e.g. His name begins with a "K."
• Sometimes to enclose document titles and parts, and addresses within a sentence, e.g. Her book, "Roget's International Thesaurus," is a bestseller.
• For quotes within quotes, alternate between double quotation marks and single marks. Use three marks together if two quoted elements end at the same time, e.g. She said, "Paul told me, 'I love you.'"

Quotation Marks (Single) (' ')

• Single quotation marks are used to enclose a quotation within a quotation and may be used around words that are special terms or for words referred to as words or sentences referred to as sentences.

Semicolon (;)

Punctuation sometimes regarded as a weak period or strong comma and used in ways similar to periods and commas. A semicolon can mark the end of a clause and indicate that a clause following is closely related to the previous clause. A semicolon can also divide a sentence to make meaning clearer. A semicolon is placed outside quotation marks and parentheses. Uses are:

• Separates (but also links) independent clauses in place of a coordinating conjunction or ellipsis, e.g. The package was due last week; it arrived today.
• Separates (and links) independent clauses when the second clause begins with a conjunctive adverb such as: accordingly, all the same, also, as a result, besides, by the same token, consequently, furthermore, hence, however, indeed, in that case, likewise, moreover, nevertheless, on the other hand, otherwise, still, then, therefore, and thus. These usually explain or summarize preceding matter or show some kind of transition, e.g. We organized enough work for the rest of the summer; therefore, I can plod ahead.
• Clarifies meaning in long sentences and in those with several commas. The indication of a strong pause by the semicolon helps the reader understand the meaning.
• May be used before explanation phrases and clauses as: e.g., for example, for instance, i.e., namely, that is - e.g. She is highly qualified for the job; for example, she has worked for more than twenty years as a writer and editor.
• Separates lists or phrases in a series when the phrases themselves have commas, e.g. We visited Springfield, Massachusetts; Keene, New Hampshire; and Durham, New Hampshire.

Slash (/)

Punctuation also called the virgule, diagonal, solidus, oblique, or slant. Its uses:

• A slash represents 'or' or 'and/or' in alternatives, e.g. yours/mine.
• A slash is used to separate expressions that indicate a choice, e.g. pass/fail, on/off.
• A slash may represent 'and', e.g. 1990/91, Minneapolis/St. Paul.
• A slash may represent some prepositions -- at, for, versus, with - e.g. c/o addressee, w/dressing.
• A slash represents 'per' or 'to' in measures and ratios, e.g. 2 ft./min., price/earnings ratio.
• A slash is used to separate numbers in dates, fractions, and telephone numbers, e.g. 8/25/1954.
• A slash, set off by spaces, is used to separate parts of an address or divide lines of poetry when written as continuous text, e.g. Workman Publishing / 708 Broadway / New York, New York.
• A slash is used to divide lines of poetry quoted within sentences.