Grammar
Style guide 
Apostrophes
We use an apostrophe to:
- indicate possession (dog's bone)
- replace letters in contracted words (can't)
- avoid ambiguity (dot the i's).
Possession
The apostrophe indicates ‘belonging to’ or ‘of’. For example, the boy’s game means ‘the game belonging to the boy’.
In plurals, the apostrophe comes after the plural form of the word, which may not necessarily be an ‘s’. For example, children's toys, heroes' rewards.
Adjectival possession
There is a second category of possession, called adjectival possession, and it means ‘for’ rather than ‘belonging to’ or ‘of’. For example, girls’ school (school for girls), widows’ pension (pension for widows).
This apostrophe is often dropped these days, for example, girls school and widows pension.
This ambiguity causes some debate. In New South Wales, the Roads and Traffic Authority obviously had difficulty deciding where to put the apostrophe in drivers licence. Is it your driver’s licence (belonging to you)? Or a drivers licence/drivers’ licence (a licence for driving). If it’s a licence for driving, should it be with or without an apostrophe? The RTA’s solution: driver licence. In the European Union, it’s called a driving licence.
Common problems with apostrophes
Confusing its and it’s
Its only has an apostrophe when it is short for it is. Its is already a possessive pronoun
.
It’s a wise dog that scratches its own fleas.
Using apostrophes in plurals
Apostrophes in plurals are rife but incorrect (Unique Santa Photo’s).
Using apostrophes in the wrong place
Apostrophes are often placed in the wrong place. A sign for a kids’ gym in Sydney says: Kid’s gym. That lucky kid!
Using apostrophes in plural abbreviations and dates
Plural abbreviations and dates, such as CDs, 1990s, FAQs, do not need an apostrophe.
Grammar e-book and e-newsletter
If you found this tip useful, you might like to read more grammar tips, sign up for the e-newsletter and buy