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.

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.

Noun possession rules

Noun type	Rule	Examples
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 James’s profession Laos’s population Louis’s supervisor Jesus’s disciples
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.

Only add an apostrophe when showing possession.

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

There are 4 types of shortened forms: abbreviations, contractions, acronyms and initialisms.

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.

Consider whether the possessive form is necessary or can be replaced by a descriptive phrase.

Add ‘s’ to make a plural shortened form – not apostrophe and ‘s’

Add an ‘s’ to form the plural of shortened forms such as acronyms and initialisms. Don’t write an apostrophe before the ‘s’. The same rule applies when making nouns plural.

Add an apostrophe to plural shortened forms to show possession.

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.

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.

Don’t use an apostrophe for Australian place names

Don’t use an apostrophe for Australian place names involving possessives.

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.

When the time reference is in the singular, use an apostrophe to show that the noun is singular.

Apostrophes show contractions

Apostrophes show that you have omitted letters in contractions.

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.

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’.

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.

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.

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.

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.