Apostrophes show possession and contractions. Don’t use them in descriptive phrases or to make nouns and shortened forms plural.
Apostrophes show possession
When the first of 2 consecutive nouns has an apostrophe, it means those nouns have a relationship. If the first noun in a noun phrase has an apostrophe, it means the noun is related to the other words in the phrase.
The type of relationship shown by the apostrophe differs, but all are known collectively as ‘possessives’ and sometimes as ‘genitives’.
On this page, ‘possession’ or ‘possessive’ means any relationship between nouns – or between words in a noun phrase – that is shown by an apostrophe.
- This is Ariah’s desk.
- We enjoy Adelaide’s music festivals.
- They are the minister’s chief of staff.
- It was a winter’s morning.
Follow the possession rules for different types of nouns
To correctly show possession by using an apostrophe, first ask, ‘Who or what is doing the possessing?’
The apostrophe goes straight after the noun that is the answer.
There are possession rules for using an apostrophe, according to the type of noun.
|Singular noun||Add an apostrophe and ‘s’||the committee’s report
our department’s plan
the bus’s passengers
the kibbutz’s energy needs
|Singular noun of 2 or more words, the last word being a plural ending in ‘s’||Add an apostrophe only||the Australian Bureau of Statistics’ office
a Department of Social Services’ project
the United States’ representatives
|Plural nouns that end in letter ‘s’||Add an apostrophe only||both committees’ reports
the Joneses’ submission
the Sanchezes’ security passes
|Plural nouns that don’t end in ‘s’||Add an apostrophe and ‘s’||our children’s education
the sheep’s wool
the gateaux’s boxes
|Proper names ending in letter ‘s’||Add an apostrophe and another ‘s’, even if you don’t pronounce that final ‘s’||Burns’s report
|More than one noun: individual possession||Add an apostrophe and ‘s’ after each noun||Smith’s and Miller’s offices|
|More than one noun: joint possession||Add an apostrophe and ‘s’ after the last noun only||Smith and Miller’s report
Julie and Karl’s children
|Singular compound noun||Add an apostrophe and ‘s’ after the compound||the attorney-general’s speeches
the owner-occupier’s accountant
|Plural compound nouns ending in ‘s’||Add an apostrophe after the compound||all owner-occupiers’ tax concessions|
|Plural compound nouns that don’t end in ‘s’||Add an apostrophe and ‘s’ after the compound||the attorneys-general’s meeting|
Descriptive phrases don’t need an apostrophe
Some nouns are descriptive rather than possessive. In a descriptive noun phrase, the first noun modifies the second noun by operating as a definitive adjective.
Don’t use an apostrophe for these nouns.
The first noun is essential to the meaning of the second noun. For this reason, never separate the nouns in a descriptive phrase.
- workers compensation [A type of insurance]
- visitors book [A type of book]
- drivers licence [A type of licence]
Only add an apostrophe when showing possession.
- They signed the visitors book. [Descriptive: a type of book]
- Her visitor’s book was lying on the table. [Possessive: the book her visitor owns]
- She attended a directors meeting. [Descriptive: a type of meeting]
- The director’s meetings don’t have an agenda. [Possessive: the meetings of the director]
- You must hold a valid drivers licence to drive on Australian roads. [Descriptive: a type of licence]
- The officer asked to see the driver’s licence. [Possessive: the licence owned by the driver]
- Each state and territory has its own regulator to administer workers compensation. [Descriptive: a type of compensation insurance]
- Under the award, our workers’ compensation for working overtime is time off in lieu. [Possessive: a form of compensation to workers for doing overtime]
In the last 2 examples, the distinction between descriptive and possessive is subtle.
The Style Manual recognises ‘workers compensation’ in the first example as a descriptive phrase.
Although not recommended style, we acknowledge that the house styles of some government agencies require an apostrophe when using the phrase in this way.
Add an apostrophe and ‘s’ to form possessive shortened forms
Only use shortened forms if users will understand them. Make sure they are appropriate for your content’s context, purpose and tone.
Add an apostrophe and ‘s’ to show possession for shortened forms.
- Enjoy hassle-free travel with Tassie's new permit system! [Abbreviation]
- The fire destroyed some of ASIO’s files. [Acronym]
- The provisions of the bill are based on the Cth’s Act. [Contraction]
- The review approved ABS’s work plan. [Initialism]
Consider whether the possessive form is necessary or can be replaced by a descriptive phrase.
- ASIO files are stored securely.
- Qantas aircraft have an excellent safety record.
- We read several US data use agreements.
- Consultation with stakeholders is integral to ABS work plans.
Add ‘s’ to make a plural shortened form – not apostrophe and ‘s’
Add an apostrophe to plural shortened forms to show possession.
- MPs’ entitlements
- POWs’ repatriation
Don’t use a possessive when defining a shortened form
Define a shortened form the first time you use it (unless you’re certain users will understand it without a definition). Follow the spelt-out term with its shortened form in parentheses.
Avoid using a possessive apostrophe when you do this. It can be difficult to decide where to put the apostrophe and the sentence is often harder to read.
Use the shortened form rather than the full term if you mention the term again.
- The Department of Veterans’ Affairs (DVA) has information about veteran support officers on its website. DVA supports …
- Use the Moneysmart savings goal calculator from the Australian Securities and Investments Commission (ASIC). ASIC created Moneysmart to …
- Find information about veteran support officers on the Department of Veterans’ Affairs’ (DVA’s) website. DVA supports …
- Use the Australian Securities and Investments Commission’s (ASIC’s) Moneysmart savings goal calculator. ASIC created Moneysmart to …
Possessive pronouns don’t need an apostrophe
Don’t add an apostrophe to possessive pronouns.
Although the term ‘possessive pronoun’ is commonly used, it’s more accurate to divide these pronouns into possessive pronouns and determiners (also called ‘possessive determiners’).
If a pronoun appears before the noun, it is a determiner. If a pronoun appears in place of the noun, it is a possessive pronoun.
Don’t use an apostrophe for either type of pronoun.
- This is your office. That is theirs. [‘your’ is a determiner, ‘theirs’ is a possessive pronoun]
- The fault is ours. [‘ours’ is a possessive pronoun]
- Put the report in its place. [‘its’ is a determiner]
- It was my idea not yours! [‘my’ is a determiner, ‘yours’ is a possessive pronoun]
Don’t use an apostrophe for Australian place names
Don’t use an apostrophe for Australian place names involving possessives.
- Kings Cross
- Mrs Macquaries Chair
Don’t use an apostrophe for periods of time
Noun phrases about plural time periods don’t need apostrophes because they’re usually descriptive, not possessive.
In phrases such as ‘6 months retired’ or ‘5 months pregnant’, the time periods are clearly adjectival. They don’t show possession.
Other noun phrases aren’t possessive because they are conversational shorthand for an ‘of’ phrase. For example, ‘in 4 days time’ is shorthand for ‘in 4 days of time’.
Some styles use an apostrophe to stand for the word ‘of’ and don't use it for descriptive phrases. For many years, the Style Manual has recommended the simple rule of no apostrophe for either use.
- 6 weeks time
- 3 months wages
When the time reference is in the singular, use an apostrophe to show that the noun is singular.
- a day’s work
- the year’s cycle
Apostrophes show contractions
Apostrophes show that you have omitted letters in contractions.
- I haven’t seen the report.
- It’s a busy day at the office.
Don’t confuse ‘it’s’ (the contraction of ‘it is’ or ‘it has’) with ‘its’ (showing that ‘it’ owns something).
If you can divide ‘it’s’ into ‘it is’ or ‘it has’, then you need to use an apostrophe. ‘Its’ is a determiner and doesn’t have an apostrophe.
- It’s time to give the committee its terms of reference.
Don’t use an apostrophe to make a noun plural
No apostrophe is needed for the plural form of a noun. This type of error is known as the ‘greengrocer’s apostrophe’.
- the 2020s
- committee reports
- newer 747s
- fresh avocados
- the 2020’s
- committee report’s
- newer 747’s
- fresh avocado’s
Plural words and phrases that are not usually nouns
Don’t use an apostrophe for nouns and noun phrases formed by pluralising (and sometimes hyphenating) words that aren’t usually nouns. Two examples are ‘whys and wherefores’ and ‘what-ifs’.
The Style Manual follows the style for pluralising nouns – no apostrophe. We also prefer to use the minimal punctuation needed to make meaning clear.
If you’re unsure, check your preferred dictionary. Many popular phrases appear as entries.
- The website included a list of dos and don’ts.
- No ifs, ands or buts about it!
- Ums and ahs littered every speech.
- They made their thank-yous then left.
- The website included a list of do’s and don’t’s.
- No if’s, and’s or but’s about it!
- Um’s and ah’s littered every speech.
- They made their thank-you’s then left.
Single letter and digit plurals
Use an apostrophe before the ‘s’ for plurals of single letters and single-digit numbers. They are exceptions to the rule of not using an apostrophe for the plural form of a noun.
The apostrophe ensures that letter plurals are easier to understand.
Don’t italicise these plurals or place them in quotation marks.
- Binary code uses 0’s and 1’s.
- Dot your i’s and cross your t’s when you edit the report.
- This tongue twister has too many s’s!
Apostrophes can stand in for sounds
Apostrophes show sounds in words from other languages.
This occurs when words in certain languages are ‘transliterated’, that is, when words in other languages are written using letters of the English alphabet.
In our examples, the apostrophe is a transliteration of a letter with a diacritic mark that represents the sound of a glottal stop.
If you’re unsure whether an apostrophe is needed, consult your dictionary for the preferred spelling.
- She was reading the Qur’an.
- Ge’ez is an ancient language from Ethiopia.
Some official names have apostrophes
An apostrophe can form part of the official name of an organisation (or entity). Use an apostrophe if the organisation does.
To find the spelling an organisation prefers, check its correct name by using reliable sources.
- National Farmers’ Federation
- Australian Workers Union
- Energy Ministers’ Meeting
- Education Ministers Meeting
- Infrastructure and Transport Senior Officials’ Committee
- Basin Officials Committee
The digital edition consolidates information about apostrophes and provides more examples to help users understand correct usage. New guidance includes: shortened forms, determiners, plurals that are not usually nouns (noun coinage) and apostrophes that stand in for sounds.
The sixth edition had information about apostrophes in several sections.
The Content Guide had brief advice about using apostrophes.
About this page
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University of Chicago (2017) ‘7.14: Plurals of noun coinages’, Chicago manual of style, 17th edn, University of Chicago Press, Chicago.
Australian Government (n.d.) Directory, directory.gov.au, accessed 5 September 2021.
Cambridge University (2021) ‘Pronouns: possessive (my, mine, your, yours, etc.)’, Cambridge dictionary, dictionary.cambridge.org, accessed 22 October 2021.
Davies WM (n.d.) Apostrophes [PDF 192KB], Helpsheet: Giblin Eunson Library, University of Melbourne website [cached resource], accessed 2 September 2021.
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