From Wikipedia, the free encyclopedia
The apostrophe ( ’ ) is a punctuation mark, and sometimes a diacritic mark, in languages written in the Latin alphabet. In English, it has two main functions: it marks omissions; and it assists in marking the possessives of all nouns and many pronouns. (In strictly limited cases, it is sometimes also allowed to assist in marking plurals, but most authorities are now against such usage; see below.) According to the OED, the word comes ultimately from Greek ἡ ἀπόστροφος [προσῳδία] (hē apóstrophos [prosōidía], the [accent of] "turning away", or elision), through Latin and French.
apostrophe ( ', ’ )
ampersand ( & )
 English language usage
 Possessive apostrophe
An apostrophe is used to indicate possession.
- For most singular nouns, the ending ’s is added, e.g. the cat’s whiskers.
- If the word is plural and already ends in an s, then instead only an apostrophe is added, for example my nieces’ weddings. (This does not apply to plurals that do not end in an s, for example the children’s toys.)
- If the word ends in an s but is singular, practice varies as to whether to add ’s or only an apostrophe. (For discussion on this and the following points, see below.) In general, a good practice is to follow whichever spoken form is judged best: Boss’s shoes, Mrs. Jones’ hat (or Mrs. Jones’s hat, if that spoken form is preferred). In many cases, both spoken and written forms will differ between people.
- Some people like to reflect standard spoken practice in special cases like these: for convenience’ sake, for goodness’ sake, for appearance’ sake, etc. Others prefer to add ’s in the standard way: for convenience’s sake. Still others prefer to omit the apostrophe when there is an s sound before sake: for morality’s sake, but for convenience sake.,
- Compound nouns have their singular possessives formed with an apostrophe and an s at their end, in accordance with the rules given above: the Attorney-General’s husband; the Minister for Justice’s religion; her father-in-law’s new wife. In the examples just given, the plurals are formed with an s that does not occur at the end: Attorneys-General, etc. An interesting problem therefore arises with the possessive plurals of these compounds. Sources that rule on the matter appear to favour the following forms, in which there is both an s added to form the plural, and a separate s added for the possessive: the Attorneys-General’s husbands; the Ministers for Justice’s religions; their fathers-in-law’s new wives.
- No apostrophe is used in the following possessive pronouns and adjectives: yours, his, hers, ours, its, theirs, and whose. (Very many people wrongly use it’s for the possessive of it; but authorities are unanimous that it’s can only properly be a contraction of it is or it has.) All other possessive pronouns ending in s do take an apostrophe: one’s; everyone’s; somebody’s, nobody else’s, etc. With plural forms, the apostrophe follows the s, as with nouns: the others’ husbands (but compare They all looked at each other’s husbands, in which both each and other are singular).
To illustrate that possessive apostrophes matter, and that their usage affects the meaning of written English, consider these four phrases (listed in Steven Pinker’s The Language Instinct), each of which has a meaning distinct from the others:
- my sister’s friend’s investments (I have one sister and she has one friend.)
- my sisters’ friends’ investments (I have many sisters and they have many friends.)
- my sisters’ friend’s investments (I have many sisters and they have one friend.)
- my sister’s friends’ investments (I have one sister and she has many friends.)
Kingsley Amis, on being challenged to produce a sentence whose meaning depended on a possessive apostrophe, came up with:
- “Those things over there are my husbands.”
Which, if an apostrophe were added, would read "Those things over there are my husband's [items].”
 Apostrophe showing omission
An apostrophe is commonly used to indicate omitted characters:
- It is used in abbreviations, as gov’t for government, or ’70s for 1970s. Note: Currently, apostrophes are generally omitted when letters are removed from the start of a word. For example, it is not common to write ’bus, ’phone, ’net. However, if the shortening is unusual or dialectal, the apostrophe may still be used to mark it (e.g., ’bout for about, ’less for unless). Sometimes a misunderstanding of the original form of a word results in an incorrect contraction. A common example: ’til for until, though till is in fact the original form, and until is derived from it.
- It is used in contractions, such as can’t from cannot, it’s from it is or it has, and I’ll from I will or I shall.
 Use in forming certain plurals
An apostrophe is used by some writers to form a plural for abbreviations, acronyms, and symbols where adding just s rather than ’s may leave things ambiguous or inelegant. While British English formerly endorsed the use of such apostrophes after numbers and dates, this usage has now largely been superseded. Some specific cases:
- It is generally acceptable to use apostrophes to show plurals of single lower-case letters, such as be sure to dot your i's and cross your t's. Some style guides would prefer to use a change of font: dot your is and cross your ts. Upper case letters need no apostrophe as there is no risk of misreading: I got three As in my exams. 
- For the plural of abbreviations, an apostrophe is widely regarded as incorrect, so CDs is preferable to CD’s.
- For groups of years, the apostrophe at the end cannot be regarded as necessary, since there is no possibility of misreading. For this reason, most authorities prefer 1960s to 1960’s (although the latter is a common Americanism), and 90s or ’90s to 90’s or '90's.
- The apostrophe is sometimes used in forming the plural of numbers (for example, 1000’s of years); however, as with groups of years, it is unnecessary: there is no possibility of misreading. Most sources are against this usage.
- Also, the apostrophe is used in plurals of symbols, though, because there can be no misreading, this is also wrong.  That page has too many &s and #s on it.
- Finally, a few sources accept its use in an alternative spelling of the plurals of a very few short words, such as do, ex, yes, no, which become do’s, ex’s, etc. In each case, dos, exes, yesses and noes would be preferred by most authorities. Nevertheless, many writers are still inclined to use such an apostrophe when the word is thought to look awkward or unusual without one.
 Non-English names
- Irish surnames often contain an apostrophe after an O, for example O’Reilly. This arose from a rendering of the Irish Ó.
- Some Scottish and Irish surnames use an apostrophe after an M, for example M’Gregor. The apostrophe here may be seen as marking a contraction where the prefix Mc or Mac would normally appear. (Note, however, that in earlier and meticulous current usage, it is ‘ – a kind of reversed apostrophe that is sometimes called a turned comma, which eventually came to be written as the letter c, whose shape is similar.)
- French and Italian surnames sometimes contain apostrophes, e.g. D’Angelo. Other times, foreign names that would have used an accented character have an apostrophe substituted, e.g. DuPre’ for du Pré.
- The English possessive of French names ending in a silent s is rendered differently by different authorities. Some prefer Descartes’ and Dumas’, while others insist on Descartes’s and Dumas’s. Certainly an s sound (or strictly a z sound, with Dumas) is pronounced in these cases; the theoretical question is whether the existing s is the one that is sounded, or whether another s needs to be supplied. A similar problem arises with French names ending in silent x. Many authorities prescribe possessives with an added s: Sauce Périgueux’s main ingredient is truffle; but an apostrophe alone is also acceptable. For possessive plurals of words ending in silent x or s, the few authorities that address the issue at all call for an added s, and require that the apostrophe precede the s: The Loucheux’s homeland is in the Yukon; Compare the two Dumas’s literary achievements. As usual in punctuation, the best advice is to respect soundly established practice, and beyond that to strive for simplicity, logic, and especially consistency.
 Geographic names
United States place names generally do not use the possessive apostrophe. The United States Board on Geographic Names, which has responsibility for formal naming of municipalities and geographic features, has deprecated the use of possessive apostrophes since 1890. Only five names of natural features in the U.S. are officially spelled with a genitive apostrophe (one example being Martha's Vineyard). On the other hand, Britain has Bishop's Stortford, Bishop's Castle and King's Lynn (but St Albans, St Andrews and St Helens) and, while Newcastle United play at St James' Park, and Exeter City at St James Park, London has a St James’s Park (this whole area of London is named after St James's Church, Piccadilly). The special circumstances of the latter case may be this: the customary pronunciation of this place name is reflected in the addition of an extra -s; since usage is firmly against a doubling of the final -s without an apostrophe, this place name has an apostrophe. This could be regarded as an example of a double genitive: it refers to the park of the church of St James. None of this detracts from the fact that omission of the apostrophe in geographical names is becoming a clear standard in most English-speaking countries, including Britain and Australia.
 Business names
Where a business name is based on a family name, it will typically take no apostrophe, thus McMenamins Pub, or Roches Stores. This may sometimes be due to a lack of grammatical knowledge by their founders, but usually to the same strong aversion to the apostrophe evident in geographic names. Names based on a first name are more likely to take an apostrophe (Joe’s Crab Shack), perhaps because there is no ambiguity about whether the putative owner is an individual. The Apostrophe Protection Society has campaigned for large retailers such as Harrods, Currys and Selfridges to reinstate their missing punctuation. A spokesperson for Barclays plc stated, "It has just disappeared over the years. Barclays is no longer associated with the family name."
 Possessive forms of nouns ending in s
The special case of non-English names ending in silent s, z, or x (e.g. Descartes) is dealt with above.
- When the noun is a normal plural with an added s, no extra s is added in the possessive, so pens’ lids (where there is more than one pen) is correct rather than pens’s lids. If the plural is not one that is formed by adding s, add an s for the possessive, after the apostrophe: children’s hats, women’s hairdresser, some people’s eyes, some peoples’ recent emergence into nationhood (peoples being the plural of the singular people, here). These principles are universally accepted.
- Respected sources require that almost all singular nouns, including those ending in an s, a z, or an x, have possessive forms with an extra s after the apostrophe. Examples include the Modern Language Association, The Elements of Style, The Economist, and Purdue University’s Online Writing Lab. Such sources would demand possessive singulars like these: Senator Jones’s umbrella; Mephistopheles’s cat.
- Rules that modify or extend this principle have included the following:
- If the singular possessive is difficult or awkward to pronounce with an added s sound, do not add an extra s; these exceptions are supported by University of Delaware, The Guardian, Emory University’s writing center, and The American Heritage Book of English Usage. Such sources permit possessive singulars like these: Socrates’ later suggestion; James’s house, or James’ house, depending on which pronunciation is intended.
- As a particular case, Jesus’ is very commonly written instead of Jesus’s, even by people who would otherwise add ’s in, for example, James’s or Chris’s; Jesus’ is referred to as “an accepted liturgical archaism” in Hart’s Rules.
- Similar examples of notable names ending in an s that are often given a possessive apostrophe with no additional s include Dickens and Williams. There is often a policy of leaving off the additional s on any such name, but this can prove problematic when specific names are contradictory (for example, St James’ Park in Newcastle [the football ground] and the area of St James’s Park in London). See points above; for more details on practice with geographic names, see the relevant section above.
The use of the apostrophe to mark the English possessive ultimately derives from the Old English genitive case, indicating possession, which often ended in the letters -es, which evolved into a simple s for the possessive ending. An apostrophe was later added to mark the omitted e; this came into general use in the 17th century. The ’s ending is sometimes called the Saxon genitive, but is now generally considered a clitic.
 Non-standard English use
 Greengrocers’ apostrophes
Apostrophes used incorrectly to form plurals are known as greengrocers’ apostrophes (or grocers’ apostrophes, or sometimes humorously greengrocers apostrophe’s). The practice comes from the identical sound of the plural and possessive forms of most English nouns. It is often considered a form of hypercorrection coming from a widespread ignorance of the proper use of the apostrophe or of punctuation in general. Lynne Truss, author of Eats, Shoots & Leaves, points out that before the 19th Century, it was standard orthography to use the apostrophe to form a plural of a foreign-sounding word that ended in a vowel (e.g. banana's, folio's, logo's, quarto's, pasta's, ouzo's) to clarify pronunciation. Truss says this usage is no longer considered proper in formal writing.
It is believed that the term was first coined in the middle of the twentieth century by a teacher of languages working in Liverpool, at a time when such mistakes were common in the handwritten signs and advertisements of greengrocers, e.g., “Apple’s 1/- a pound, orange’s 1/6d a pound”. In recent years, this misuse has become increasingly frequent in other forms of advertisement, particularly those of small businesses, e.g., from Hackney Market in London, UK: “Christmas Card’s”. Some have argued that its use in mass communication by employees of well-known companies has led to the less grammatically able assuming it to be correct and adopting the habit themselves.
The same error is sometimes made by non-native speakers of English, and this hyperforeignism has been formalised in some pseudo-anglicisms. For example, the French word pin's (from English pin) is used (with the apostophe in both singular and plural) for collectible lapel pins. Also, there is an Andorran football club called FC Rànger's (after such British clubs as Rangers F.C.).
 Omitting the apostrophe
While the greengrocers’ apostrophe is more likely to be found within small businesses, the UK’s largest supermarket chain, Tesco, has a habit of omitting the mark where it should be included. Its in-store signage advertises (among other items) “mens magazines”, “girls toys”, “kids books” and “womens shoes”. The author Bill Bryson lambasts Tesco for this reason in his book Troublesome Words, stating, “The mistake is inexcusable and those who make it are linguistic Neanderthals.”
George Bernard Shaw, a proponent of English spelling reform on phonetic principles, argued that the apostrophe was mostly redundant. He did not use it for spelling “cant” or “hes” when writing Pygmalion. He did however allow “I’m” and “it’s”. Lewis Carroll made greater use of apostrophes, and frequently used “ca’n’t” and “sha’n’t”. Neither author's use has become widespread.
 Other languages
 As a mark of elision
In many languages, especially European languages, the apostrophe is used to indicate the elision of one or more sounds, as in English:
- For example, in Afrikaans it is used to show that letters have been omitted from words. The most common use is in the indefinite article ’n which is a contraction of een meaning ‘one’ (the number). As the initial ‘e’ is omitted and cannot be capitalised, if a sentence begins with ’n the second word in the sentence is capitalised. For example: ’n Boek is groen. “A book is green.”
- In Danish, where some very common words having pronunciation that does not match the spelling, rendering it in writing is informal, yet wildly popular in all kinds of written commercial materials. Thus, one can readily see Ta' mig med (“Take me with [you]”) next to a stand with advertisement leaflets; that would be written Tag mig med in standard ortography. As in German, the apostrophe must not be used to indicate possessive, except for when there's already an s present in the base form, as in Lukas' bog. Sometimes an apostrophe is also used to join the enclitic definite article to words of foreign origin, or other words which would otherwise look awkward. Thus, one would write IP'en to mean “the IP address”. There's some variation in what is considered “awkward enough” to warrant an apostrophe, for instance, long-established words such as firma (company) or niveau (level) might be written firma'et and niveau'et, but will generally be seen without an apostrophe.
- In the Dutch language, it is also used to indicate omitted characters. For example, the indefinite article een can be shortened to ’n, the definite article het can be shortened to ’t. When this happens with the first word of a sentence, only the second word of the sentence is capitalised. In general, this way of using the apostrophe is considered non-standard, except for ’s morgens, ’s middags, ’s avonds, ’s nachts (des morgens/middags/avonds/nachts: at morning/afternoon/evening/night). In addition, however, the apostrophe is used for plurals where the singulars end with certain vowels, e.g. foto’s, taxi’s, and for the genitive of proper names ending with these vowels, e.g. Anna’s, Otto’s. These are in fact elided vowels; use of the apostrophe prevents spellings like fotoos and Annaas.
- In the French phrases coup d’état and maître d’hôtel (the latter often shortened to maître d’, when used by English speakers), the vowel in the preposition de (of) is elided because the word which follows it also starts with a vowel, or a silent consonant followed by a vowel. This is common in Italian and Catalan, too.
- In German, this is very similar: an apostrophe is used only to indicate omitted letters. It must not be used for plurals or most of the possessive forms (Max’ Vater being an exception, for instance), both usages which are widespread, but deemed wrong. (See article Apostrophitis in the German Wikipedia.)
 To separate morphemes
- In Estonian, apostrophes can be used in the declension of some foreign names to separate the stem from any declension endings; e.g., Monet' or Monet'sse for the genitive case and illative case, respectively, for (the famous painter) "Monet".
- In Polish, apostrophe is used exclusively for marking inflection of words and word-alike elements (ie. acronyms) whose spelling conflicts with normal rules of which inflection form to choose, this mainly affects foreign words and names. Thus, for instance, one would write Kampania Ala Gore'a for “Al Gore's campaign”. In this example, “Ala“ is spelt without an apostrophe, as its spelling and pronunciation fit into normal Polish rules. “Gore'a“, however, needs it, as “e” disappears from the pronunciation, changing its inflection pattern. There is a widespread misunderstanding of this rule, which would rather have apostrophe after all foreign words, regardless of their pronunciation, thus rendering the above into (incorrect) Kampania Al'a Gore'a. This effect is somewhat akin to the greengrocers’ apostrophes (see above).
- In Turkish, proper nouns are capitalized and an apostrophe is inserted between the noun and any following suffix, e.g. New York’da “in New York”, in contrast with okulda “in the school”.
 As a mark of palatalization
- In the Belarusian and Ukrainian languages, the apostrophe is used between a consonant and the following “soft” (iotified) vowel (е, ё, є, ю, я) to indicate that no palatalization of the preceding consonant takes place, and the vowel is pronounced in the same way as at the beginning of the word. The same function is served by the hard sign in some other Cyrillic alphabets.
- In some transliterations from the Cyrillic alphabet (of Belarusian, Russian, or Ukrainian language), the apostrophe is used to replace the soft sign (ь, indicating palatalization of the preceding consonant), e.g., Русь is transliterated Rus’ according to the BGN/PCGN system. Confusingly, some of these transliteration schemes use a double apostrophe ( ” ) to represent the apostrophe in Cyrillic text, e.g. Ukrainian слов’янське (“Slavic”) is transliterated as slov”yans’ke.
- Some Karelian orthographies use an apostrophe to indicate palatalization, e.g. n’evvuo “to give advice”, d’uuri “just (like)”, el’vüttiä “to revive”.
 As a glottal stop
Other languages and transliteration systems use the apostrophe as a letter, denoting the glottal stop.
- Guarani, where it is called puso /puˈso/, as in the words ñe’ẽ, ka’a, a’ ỹ.
- Hawaiian, where is it called the ʻokina (ʻ), often rendered as ('), and considered a letter of the alphabet.
- The constructed Klingon language.
 Other uses
- In the Czech and Slovak languages, common typographic rendering (at least for some typefaces) of caron over lowercase t, d, l, and uppercase L consonants (ď, ť, ľ, Ľ) looks a lot like an apostrophe, but it is incorrect to use apostrophe instead (compare previous example with incorrect d’, t’, l’, L’ or d', t', l', L'). In Slovak, there is also l with acute accent (ĺ, Ĺ). In Slovak, it is used to indicate elision in certain words (tys’ as an abbreviated form of ty si), however, these elisions are restricted to poetry.
- In Finnish, one of the consonant gradation patterns is the change of a ‘k’ into a hiatus, e.g. keko → keon “a pile → pile’s”. This hiatus has to be indicated in spelling with an apostrophe, if a long vowel or a diphthong would be immediately followed by the final vowel, e.g. ruoko → ruo’on, vaaka → vaa’an. (This is in contrast to compound words, where the same problem is solved with a hyphen, e.g. maa-ala “land area”.) The same meaning for an apostrophe, a hiatus, is used in poetry to indicate contractions, e.g. miss’ on for missä on “where is”.
- In Jèrriais, one of the uses of the apostrophe is to mark gemination, or consonant length. For example, t’t represents /tː/, s’s /sː/, n’n /nː/, th’th /ðː/, and ch’ch /ʃː/ (as contrasted to /t/, /s/, /n/, /ð/, and /ʃ/).
- In the Hànyǔ Pīnyīn system of romanization for Standard Mandarin (the main Chinese language), the apostrophe is sometimes used to separate syllables in a word where ambiguity could arise. Example: the standard romanization for the name of the city Xi'an includes an apostrophe to distinguish it from a single-syllable word xian. This usage is inconsistent, however, and is conventionally not applied in many placenames. Example: Jinan, which pedantically ought to be given as Ji'nan to disambiguate from a possible Jin an.
 Alternative uses
- The vertical typewriter apostrophe ( ' ) is often used to approximate the prime ( ′ ) (used as a symbol to indicate measurement in feet or arcminutes); the right single quotation mark apostrophe is less appropriate in this context.
- In science fiction, the apostrophe is often used to decorate alien names.
 Computers and Unicode
- ( ' ) Vertical typewriter apostrophe (Unicode name “apostrophe” or “apostrophe-quote”), Unicode and ASCII character 39, or hexadecimal U+0027.
- ( ’ ) Punctuation apostrophe (“right single quotation mark” or “single comma quotation mark”), U+2019.
- ( ʼ ) Letter apostrophe (“modifier letter apostrophe”), U+02BC.
In most cases, the preferred apostrophe character is the punctuation apostrophe (distinguished as typographic, or curly apostrophe). But historically, only the vertical typewriter apostrophe has been present on computer keyboards and in 7-bit ASCII character encoding. The typographic apostrophe is in different positions of the many 8-bit encodings.
So in practice, the typewriter apostrophe is much more commonly used by writers and editors. For the same historic reasons, the typewriter apostrophe is a highly overloaded character position. In ASCII, it represents a right single quotation mark, left single quotation mark, apostrophe punctuation, vertical line, or prime (punctuation marks) or an apostrophe modifier or acute accent (modifier letters).
In some cases an apostrophe is not considered punctuation which separates letters, but as a letter in its own right; a letter apostrophe. Examples are in some national languages where the apostrophe is considered a letter (e.g., the Cyrillic Azerbaijani alphabet), or in some transliterations (e.g., transliterated Arabic glottal stop, hamza, or transliterated Cyrillic soft sign). As the letter apostrophe is seldom used in practice, the Unicode standard cautions that one should never assume text is coded thus.
The Nenets language has single and double letter apostrophes:
- ( ˮ ) Double letter apostrophe (Unicode name “modifier letter double apostrophe”), U+02EE.
 Entering apostrophes
During text entry on computers, some programs automatically convert to the appropriate apostrophe or quotation mark characters; the so-called “smart quotes” feature. Apostrophes and quotation marks that are not automatically altered by computer programs are known as “dumb quotes”. Such conversion can be provided by word processing software as you type, or on web servers after submitting text in a form field, e.g., on weblogs or free encyclopedias. Many such software programs incorrectly enter an opening quotation mark for a leading apostrophe (e.g., in abbreviations of years: ‘04 rather than the correct ’04 for 2004), or an apostrophe for a prime (e.g., latitude 49° 53’ 08” rather than the correct 49° 53′ 08″).
A useful quick solution to get such cases right in Microsoft Word is to type two apostrophes (sometimes using a space as well, as required), and then simply delete the first.
On Microsoft Windows, Unicode special characters can be entered explicitly by holding the ALT key and typing the four-digit decimal code position of the character. An apostrophe is entered by holding alt while typing 8217 on the numeric keypad (at the right side of a standard keyboard). (Typing a three-digit code will enter a character value in the current code page, which may not correspond to its Unicode value.)
On the Apple Macintosh, special characters are typed while holding down the option key, or option and shift keys together. In Macintosh English-language keyboard layouts, an apostrophe is typed with the shortcut option-shift-] .
In publishing, typewriter apostrophes are generally converted to typographic apostrophes. Because of the egalitarian nature of electronic publishing, and the low resolution of computer monitors in comparison to print, typewriter apostrophes have been considered much more tolerable on the Web. However, due to the wide adoption of the Unicode text encoding standard, near-universal Web browser support, higher-resolution displays, and advanced anti-aliasing of text in modern operating systems, the use of typographic apostrophes is becoming common on Web sites by discerning designers. Unfortunately, such use is not always done in accordance with the standards for character sets and encodings, as mentioned more fully below.
 Eight-bit encodings
Older 8-bit character encodings, such as ISO-8859-1, Windows CP1252, or MacRoman, universally support the typewriter apostrophe in the same position, 39, inherited from ASCII (as does Unicode). But most of them place the typographic apostrophe in different positions. ISO-8859-1, the most common encoding used for web pages, omits the typographic apostrophe altogether.
Microsoft Windows CP1252 (sometimes incorrectly called ANSI or ISO-Latin) is a duplicate of ISO-8859-1, with 27 additional characters in the place of control characters (in the range from 128 to 159). Microsoft software usually treats ISO-8859-1 as if it were CP1252. The wide adoption of Microsoft’s web browser and web server has forced many other software makers to adopt this as a de facto convention—in some cases contravening established standards unnecessarily (e.g., some applications use CP1252 character values in HTML numeric references, where Unicode values are required, and would be sufficient for interoperation with MS software). Consequently, the typographic apostrophe and several other characters are handled inconsistently by web browsers and other software, and can cause interoperation problems.
- The pop group Hear'Say [sic] used an apostrophe in its name. In her book Eats, Shoots & Leaves, Lynne Truss states that "the naming of Hear'Say in 2001 was [...] a significant milestone on the road to punctuation anarchy."
- Apostrophe (') was also a popular record by Frank Zappa.
- ^ “The English form apostrophe is due to its adoption via French, and its current pronunciation as four syllables is due to a confusion with the rhetorical device apostrophé” (W. S. Allen, Vox Graeca. The pronunciation of classical Greek, 3rd edition, 1988. Cambridge university press, Cambridge, p. 100, note 13).
- ^ DummiesWorld Wide Words. Retrieved on March 13, 2007.
- ^ Style Guide, US Department of Justice, Bureau of Justice Statistics, http://www.ojp.usdoj.gov/bjs/pub/pdf/bjssg.pdf
- ^ The United States Government Printing Office Style Manual 2000, http://www.gpoaccess.gov/stylemanual/2000/chapter_txt-8.html
- ^ a b c d Purdue University Online Writing Lab: The Apostrophe. Retrieved on March 13, 2007.
- ^ Guide to Punctuation, Larry Trask, University of Sussex.
- ^ AskOxford.com
- ^ Times Online: Harrods told to put its apostrophe back.
- ^ Truss, Lynn. Eats, Shoots & Leaves. pp. 63-5.
- ^ Christina Cavella and Robin A. Kernodle. "How the Past Affects the Future: The Story of the Apostrophe" (PDF). American University. Retrieved on 2006-10-26.
- ^ http://www.wwnorton.com/nto/20century/topic_4/shaw.htm
- ^ http://www.dace.co.uk/apostrophe.htm
- Gibaldi, Joseph. MLA Handbook for Writers of Research Papers. New York: Modern Language Association, 2003.
- Truss, Lynne. Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation, 2003. Gotham Books, Toronto (North American edition). ISBN 1-59240-087-6