All Topics  
Serial comma

 

   Email Print
   Bookmark   Link






 

Serial comma



 
 
The serial comma (also known as the Oxford comma or Harvard comma) is the comma
Comma (punctuation)

The comma is a punctuation mark. It has the same shape as an apostrophe or single closing quotation mark in many typefaces, but it differs from them in being placed on the baseline of the text....
 used immediately before a grammatical conjunction
Grammatical conjunction

In grammar, a conjunction is a part of speech that connects two words, phrases or clauses together. This definition may overlap with that of other parts of speech, so what constitutes a "conjunction" should be defined for each language....
 (nearly always and or or; sometimes nor) that precedes the last item in a list of three or more items. The phrase "Portugal, Spain, and France", for example, is written with the serial comma, while "Portugal, Spain and France", identical in meaning, is written without it.

There is no global consensus among writers or editors on the use of the serial comma.






Discussion
Ask a question about 'Serial comma'
Start a new discussion about 'Serial comma'
Answer questions from other users
Full Discussion Forum



Encyclopedia


The serial comma (also known as the Oxford comma or Harvard comma) is the comma
Comma (punctuation)

The comma is a punctuation mark. It has the same shape as an apostrophe or single closing quotation mark in many typefaces, but it differs from them in being placed on the baseline of the text....
 used immediately before a grammatical conjunction
Grammatical conjunction

In grammar, a conjunction is a part of speech that connects two words, phrases or clauses together. This definition may overlap with that of other parts of speech, so what constitutes a "conjunction" should be defined for each language....
 (nearly always and or or; sometimes nor) that precedes the last item in a list of three or more items. The phrase "Portugal, Spain, and France", for example, is written with the serial comma, while "Portugal, Spain and France", identical in meaning, is written without it.

There is no global consensus among writers or editors on the use of the serial comma. Most authorities on American English
American English

PhonologyIn many ways, compared to English language in England, North American English is conservative in its phonology. Some distinctive accents can be found on the East Coast of the United States , partly because these areas were in contact with England, and imitated prestigious varieties of English English at a time when those varieties we...
 recommend its use, but it is not so frequently used in British English
British English

British English or UK English is the broad term used to distinguish the forms of the English language used in the United Kingdom from forms used elsewhere....
 (see extended treatment below, including a survey of published recommendations in Usage and subsequent sections). In many languages (e.g., French
French language

French is a Romance language spoken around the world by around 80 million people as first language, by 190 million as second language, and by about another 200 million people as an acquired tongue, with significant speakers in 54 countries....
, Italian
Italian language

Italian is a Romance languages spoken by about 63 million people as a first language, primarily in Italy. In Switzerland, Italian is one of four Linguistic geography of Switzerlands....
, Polish
Polish language

Polish , an official language of Poland, has the largest number of speakers of any West Slavic languages. Polish-speakers use the language in a uniform manner through most of Poland, and it has a regular orthography....
, Spanish
Spanish language

Spanish or Castilian is a Romance languages that originated in northern Spain, and gradually spread in the Kingdom of Castile and evolved into the principal language of government and trade....
) the serial comma is not normally used, although it may be employed in cases where it aids clarity or the prosody
Prosody (linguistics)

In linguistics, prosody is the rhythm, stress , and intonation of connected speech . Prosody may reflect various features of the speaker or the utterance: the emotional state of a speaker; whether an utterance is a statement, a question, or a command; whether the speaker is being ironic or sarcastic; emphasis, contrast, and focus ; or othe...
 to be used when reading.

Arguments for and against


Arguments typically advanced for use of the serial comma by default include:
  1. that it better matches the spoken cadence of sentences;
  2. that it sometimes reduces ambiguity
    Syntactic ambiguity

    Syntactic ambiguity is a property of Sentence s which may be reasonably interpreted in more than one way, or reasonably interpreted to mean more than one thing....
    ;
  3. that its use matches practice with other means of separating items in a list (example: when semicolons are used to separate items, a semicolon is consistently included before the last item, even when and or or is present).


Arguments typically advanced for avoidance of the serial comma by default include:
  1. that absence of the comma better matches the spoken cadence of sentences;
  2. that use of the comma is against conventional practice;
  3. that use of the comma may introduce ambiguity (see examples below);
  4. that the comma is redundant, since the and or the or serves by itself to mark the logical separation between the final two items.


Many sources, however, are against both automatic use and automatic avoidance of the serial comma, making recommendations in a more nuanced way (see Usage and subsequent sections).

Ambiguity


Resolving ambiguity

Use of the serial comma can sometimes remove ambiguity. Consider the possibly apocryphal book dedication quoted by Teresa Nielsen Hayden
Teresa Nielsen Hayden

Teresa Nielsen Hayden is an American science fiction editor, science fiction fanzine writer, essayist, and teacher. She works for Federated Media Publishing Inc where she edits the comment section for the blog Boing Boing....
:
To my parents, Ayn Rand and God.
There is ambiguity about the writer's parentage, because Ayn Rand and God can be read as in apposition
Apposition

Not to be confused with Dislocation , which are grammatically incorrectApposition is a grammar construction in which two elements, normally noun phrases, are placed side by side, with one element serving to define or modify the other....
 to my parents, leading the reader to believe that the writer refers to Ayn Rand
Ayn Rand

Ayn Rand , was a Russian-American novelist, philosopher, playwright, and screenwriter. She is known for her best-selling novels and for developing a philosophical system called Objectivism ....
 and God
God

God is a deity in theism and deism religions and other belief systems, representing either the sole deity in monotheism, or a principal deity in polytheism....
 as his or her parents. A comma before and removes the ambiguity:
To my parents, Ayn Rand, and God.
Consider also:
My favourite types of sandwiches are pastrami, ham, cream cheese and peanut butter and jelly.
According to the two most plausible interpretations of this sentence, four kinds of sandwich are listed. But it is uncertain which are the third and fourth kinds. Adding a serial comma removes this ambiguity. With a comma after peanut butter, the kinds of sandwich are these:
  1. pastrami
  2. ham
  3. cream cheese and peanut butter
  4. jelly
With a comma after cream cheese, the kinds of sandwich are these:
  1. pastrami
  2. ham
  3. cream cheese
  4. peanut butter and jelly
Some writers who normally avoid the serial comma may use one in these circumstances, though sometimes re-ordering the elements of such a list can help as well.

Creating ambiguity

Use of the serial comma can introduce ambiguity. An example would be a book dedication reading:
To my mother, Ayn Rand and God.
In the context of the no-serial-comma convention this is unambiguously a list of three, but introducing a serial comma creates ambiguity about the writer's mother, because "Ayn Rand" can then be read as in apposition
Apposition

Not to be confused with Dislocation , which are grammatically incorrectApposition is a grammar construction in which two elements, normally noun phrases, are placed side by side, with one element serving to define or modify the other....
 to "my mother" (with the commas fulfilling a parenthetical
Bracket

Brackets are punctuation marks used in pairs to set apart or interject text within other text. In computer science, the term is sometimes said to strictly apply to the square or box type....
 function):
To my mother, Ayn Rand, and God.
This ambiguity could be resolved by restating the preposition before each list item:
To my mother, to Ayn Rand, and to God.
Consider also:
Betty, a maid and a rabbit.
When the serial comma is not used, this is clearly a list of two people and a rabbit (assuming that the unlikely idea that Betty is both a maid and a rabbit is rejected), whereas
Betty, a maid, and a rabbit
may refer either to one person (Betty, who is a maid) or to two people (Betty and a maid) and a rabbit.

Unresolved ambiguity

The Times
The Times

The Times is a daily national newspaper published in the United Kingdom since 1785 when it was known as The Daily Universal Register.The Times and its sister paper The Sunday Times are published by Times Newspapers Limited, a subsidiary of News International....
 once published this unintentionally humorous description of a Peter Ustinov
Peter Ustinov

Sir Peter Alexander Ustinov CBE or ;, born Peter Alexander Baron von Ustinow, was a British actor, writer and dramatist.Ustinov was also renowned as a filmmaker, theatre director and opera director, film director, stage designer, screenwriter, comedian, humorist, newspaper and magazine columnist, radio broadcaster and television pres...
 documentary: "highlights of his global tour include encounters with Nelson Mandela
Nelson Mandela

Nelson Rolihlahla Mandela was the first President of South Africa of South Africa to be elected in a universal suffrage democratic election, serving in the office from 1994?99....
, an 800-year-old demigod and a dildo collector." This is ambiguous as it stands, but even if a serial comma were added Mandela could still be mistaken for a demigod.

Or consider "They went to Oregon with Betty, a maid, and a cook." The presence of the last comma in the list creates the possibility that Betty is a maid, reasonably allowing it to be read either as a list of two people or as a list of three people, context aside. On the other hand, removing the comma leaves the possibility that Betty is both a maid and a cook; so in this case neither the use nor the avoidance of the serial comma resolves the ambiguity.

A writer who intends that Betty, the maid, and the cook be taken as three distinct people may create an ambiguous sentence, regardless of whether the serial comma is adopted. Furthermore, if the reader is unaware of which convention is being used, both versions are always ambiguous.

These forms (among others) would remove the ambiguity:
  • They went to Oregon with Betty – a maid and a cook. (One person)
  • They went to Oregon with Betty, who is a maid and a cook. (One person)
  • They went to Oregon with Betty (a maid) and a cook. (Two people)
  • They went to Oregon with Betty – a maid – and a cook. (Two people)
  • They went to Oregon with the maid Betty and a cook. (Two people)
  • They went to Oregon with Betty and a maid and a cook. (Three people)
  • They went to Oregon with Betty, one maid and a cook. (Three people)
  • They went to Oregon with a maid, a cook, and Betty. (Three people)
  • They went to Oregon with a maid, a cook and Betty. (Three people)


In general:
  • The list x, y and z is unambiguous if y and z cannot be read as in apposition to x.
  • Equally, x, y, and z is unambiguous if y cannot be read as in apposition to x.
  • If neither y nor y[,] and z can be read as in apposition to x, then both forms of the list are unambiguous; but if y or y[,] and z can be read as in apposition to x, then both forms of the list are ambiguous.
  • x and y and z is unambiguous.


Usage

The Chicago Manual of Style, Strunk and White's Elements of Style, most authorities on American English
American English

PhonologyIn many ways, compared to English language in England, North American English is conservative in its phonology. Some distinctive accents can be found on the East Coast of the United States , partly because these areas were in contact with England, and imitated prestigious varieties of English English at a time when those varieties we...
 and Canadian English
Canadian English

Canadian English is the Variety of English language used in Canada. More than 26 million Canadians have some knowledge of English . Approximately 17 million speak English as their native language....
, and some authorities on British English
British English

British English or UK English is the broad term used to distinguish the forms of the English language used in the United Kingdom from forms used elsewhere....
 (for example, Oxford University Press
Oxford University Press

Oxford University Press is a publisher and a department of the University of Oxford in England. It is the largest university press in the world, being larger than all the American university presses combined with Cambridge University Press....
 and Fowler's Modern English Usage
Fowler's Modern English Usage

A Dictionary of Modern English Usage, often referred to as Fowler's Modern English Usage or simply as Fowler's or Fowler, is a style guide to British English usage, written by Henry Watson Fowler....
) recommend the use of the serial comma. Newspaper style guides (such as those published by The New York Times
The New York Times

The New York Times is an American daily newspaper published in New York City. The largest metropolitan newspaper in the United States, "The Gray Lady"?named for its staid appearance and style?is regarded as a national newspaper of record....
, the Associated Press
Associated Press

The Associated Press is an Media of the United States news agency. The AP is a cooperative owned by its contributing newspapers, Radio station and Television station stations in the United States, which both contribute stories to the AP and use material written by its staffers....
, The Times
The Times

The Times is a daily national newspaper published in the United Kingdom since 1785 when it was known as The Daily Universal Register.The Times and its sister paper The Sunday Times are published by Times Newspapers Limited, a subsidiary of News International....
 newspaper in the United Kingdom, and the Canadian Press
Canadian Press

The Canadian Press is Canada's national news agency established in 1917 as a vehicle to permit Canadian newspapers of the day to exchange their news and information....
) recommend against it, possibly for economy of space.

The differences of opinion on the use of the serial comma are well characterized by Lynne Truss
Lynne Truss

Lynne Truss is an England writer and journalist, best known for her popular book Eats, Shoots & Leaves....
 in her popularized style guide Eats, Shoots & Leaves
Eats, Shoots & Leaves

Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation is a non-fiction book written by Lynne Truss, the former host of the BBC Radio 4's Cutting a Dash programme....
: "There are people who embrace the Oxford comma, and people who don't, and I'll just say this, never get between these people when drink has been taken."

In Australia
Australia

Australia, officially the Commonwealth of Australia, is a country in the southern hemisphere comprising the Australia of the world's smallest continent, the major island of Tasmania, and numerous list of islands of Australia in the Indian Ocean and Pacific Oceans....
, Canada
Canada

Canada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean....
, South Africa
South Africa

The Republic of South Africa, also known by Official names of South Africa, is a country located at the southern tip of the continent of Africa....
 and the United Kingdom
United Kingdom

The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom , the UK or Britain,is a sovereign state located off the northwestern coast of continental Europe....
, the serial comma tends not to be used in non-academic publications unless its absence produces ambiguity. Many academic publishers (for example, Cambridge University Press
Cambridge University Press

Cambridge University Press is a printer and publisher granted a Royal Letters Patent by Henry VIII of England in 1534. It is the world's oldest continually operating book publisher....
) also avoid it, though some academic publishing houses in these countries do use it. The Australian Government Publishing Service's Style Manual for Authors, Editors and Printers (6th edition, 2002), as can be inferred from its title, recommends against it, except "to ensure clarity" (p. 102).

Style guides supporting mandatory use

The following style guides support mandatory use of the serial comma: The United States Government Printing Office
United States Government Printing Office

The Government Printing Office is an agency of the Legislature of the United States federal government. The office prints and provides access to documents produced by and for all three Separation of powers of the federal government, including the Supreme Court of the United States, the United States Congress, the Executive Office of the Pres...
's Style Manual:
After each member within a series of three or more words, phrases, letters, or figures used with and, or, or nor.
  • "red, white, and blue"
  • "horses, mules, and cattle; but horses and mules and cattle"
  • "by the bolt, by the yard, or in remnants"
  • "a, b, and c"
  • "neither snow, rain, nor sleet"
  • "2 days, 3 hours, and 4 minutes (series); but 70 years 11 months 6 days (age)"


Wilson Follett's Modern American Usage: A Guide (Random House, 1981), pp. 397-401:
What, then, are the arguments for omitting the last comma? Only one is cogent – the saving of space. In the narrow width of a newspaper column this saving counts for more than elsewhere, which is why the omission is so nearly universal in journalism. But here or anywhere one must question whether the advantage outweighs the confusion caused by the omission ...
The recommendation here is that [writers] use the comma between all members of a series, including the last two, on the common-sense ground that to do so will preclude ambiguities and annoyances at a negligible cost."


Chicago Manual of Style, 15th edition (University of Chicago Press, 2003), paragraph 6.19:
When a conjunction joins the last two elements in a series, a comma ... should appear before the conjunction. Chicago strongly recommends this widely practiced usage....
  • "She took a photograph of her parents, the president, and the vice president."
  • "I want no ifs, ands, or buts."
  • "The meal consisted of soup, salad, and macaroni and cheese."


Texas Law Review Manual on Usage, Style & Editing (10th ed. 2005), R. 1.16

The American Medical Association
American Medical Association

The American Medical Association , founded in 1847 and incorporated 1897, is the largest association of physicians and medical students in the United States....
 Manual of Style
, 9th edition (1998) Chapter 6.2.1:
Use a comma before the conjunction that precedes the last term in a series.
  • Outcomes result from a complex interaction of medical care and genetic, environmental, and behavioral factors.
  • The physician, the nurse, and the family could not convince the patient to take his medication daily.
  • While in the hospital, these patients required neuroleptics, maximal observation, and seclusion.


The Publication Manual
APA style

American Psychological Association style is a widely accepted style of documentation, particularly in the social sciences. APA style specifies the names and order of headings, formatting, and organization of citations and bibliography, and the arrangement of table , figures, footnotes, and appendix, as well as other manuscript and documentat...
 of the American Psychological Association
American Psychological Association

The American Psychological Association is a professional organization representing psychology in the United States, with around 148,000 members and an annual budget of around $70m....
, 5th edition (2001) Chapter 3.02:
Use a comma between elements (including before and and or) in a series of three or more items.
  • the height, width, or depth
  • in a study by Stacy, Newcomb, and Bentler


The Elements of Style
The Elements of Style

The Elements of Style is an American English writing style guide. It is one of the most influential and best-known linguistic prescription treatments of English grammar and usage in the United States....
 (Strunk and White, 4th edition 1999):
In a series of three or more terms with a single conjunction, use a comma after each term except the last.


The Oxford Style Manual, 2002, Chapter 5, section 5.3 Comma:
"For a century it has been part of OUP style to retain or impose this last serial (or series) comma consistently, [...] but it is commonly used by many other publishers both here and abroad, and forms a routine part of style in US and Canadian English. [...] Given that the final comma is sometimes necessary to prevent ambiguity, it is logical to impose it uniformly, so as to obviate the need to pause and gauge each enumeration on the likelihood of its being misunderstood – especially since that likelihood is often more obvious to the reader than the writer." (pp. 121–122)


The CSE Manual for Authors, Editors, and Publishers (Council of Science Editors, 7th edition, 2006), Section 5.3.3.1
To separate the elements (words, phrases, clauses) of a simple series of more than 2 elements, including a comma before the closing “and” or “or” (the so-called serial comma). Routine use of the serial comma helps to prevent ambiguity.


Garner's American Usage (Oxford, 2003)
Whether to include the serial comma has sparked many arguments. But it's easily answered in favor of inclusion because omitting the final comma may cause ambiguities, whereas including it never will.


Most college writing handbooks in the U.S. also advocate use of the serial comma.

Style guides opposing mandatory use

The Times
The Times

The Times is a daily national newspaper published in the United Kingdom since 1785 when it was known as The Daily Universal Register.The Times and its sister paper The Sunday Times are published by Times Newspapers Limited, a subsidiary of News International....
 style manual:

Avoid the so-called Oxford comma; say "he ate bread, butter and jam" rather than "he ate bread, butter, and jam".


The New York Times
The New York Times

The New York Times is an American daily newspaper published in New York City. The largest metropolitan newspaper in the United States, "The Gray Lady"?named for its staid appearance and style?is regarded as a national newspaper of record....
 stylebook:

In general, do not use a comma before and or or in a series: The snow stalled cars, buses and trains.


The Economist
The Economist

The Economist is an English-language weekly news and international relations publication owned by The Economist Newspaper Ltd. and edited in London....
 style manual:
Do not put a comma before and at the end of a sequence of items unless one of the items includes another and. Thus 'The doctor suggested an aspirin, half a grapefruit and a cup of broth. But he ordered scrambled eggs, whisky and soda, and a selection from the trolley.'


The AP Stylebook
AP Stylebook

The Associated Press Stylebook and Briefing on Media Law, usually called the AP Stylebook, is a style guide used on newspapers and in journalism classes in the United States....
:
Use commas to separate elements in a series, but do not put a comma before the conjunction in a simple series: The flag is red, white and blue. He would nominate Tom, Dick or Harry.


Put a comma before the concluding conjunction in a series, however, if an integral element of the series requires a conjunction: I had orange juice, toast, and ham and eggs for breakfast.


Use a comma also before the concluding conjunction in a complex series of phrases: The main points to consider are whether the athletes are skillful enough to compete, whether they have the stamina to endure the training, and whether they have the proper mental attitude.


The Australian Government
Government of Australia

The Australia is a federation constitutional monarchy under a parliamentary democracy. The Commonwealth of Australia was formed in 1901 as a result of an agreement between six self-governing British colonies, which became the six states....
 Publishing Service's Style Manual for Authors, Editors and Printers:
A comma is used before and, or, or etc. in a list when its omission might either give rise to ambiguity or cause the last word or phrase to be construed with a preposition in the preceding phrase: "There were many expeditions, including those of Sturt, Mitchell, Burke and Wills, and Darling." "The long days at work, the nights of intense study, and inadequate food eventually caused them serious health problems." "The sea, the perfume of wisteria, or a summer lunch: any of these revived memories of an easier time." "We needed to know how to get there, what time to get there, the number of participants, etc."


Generally, however, a comma is not used before and, or or etc. in a list: "John, Warren and Peter came to dinner." "Fruit, vegetables or cereals may be substituted." "Why not hire your skis, boots, overpants etc.?"


The Guardian
The Guardian

Sorry, no overview for this topic
 Style Guide
:
a comma before the final "and" in lists: straightforward ones (he ate ham, eggs and chips) do not need one, but sometimes it can help the reader (he ate cereal, kippers, bacon, eggs, toast and marmalade, and tea)


University of Oxford Writing and Style Guide:
As a general rule, do not use the serial/Oxford comma: so write ‘a, b and c’ not ‘a, b, and c’. But when a comma would assist in the meaning of the sentence or helps to resolve ambiguity, it can be used – especially where one of the items in the list is already joined by ‘and’:
They had a choice between croissants, bacon and eggs, and muesli.


External links

  • 29th edition, U.S. Government Printing Office (Washington, 2003)
  • , The Professional Training Company
  • , a poem by Elizabeth Smither