Apostrophes
Apostrophes are used for two reasons:
- to show that letters have been left out of a word (omitted letters)
- to show that something belongs to or is a part of something else (grammatical possession)
Apostrophes are not used
- when referring to decades
1920's, 1850's
1920s, 1850s - when indicating more than one of something
I like to eat tomato's
I like to eat tomatoes - when showing grammatical possession for pronouns
our's, your's, her's, it's
ours, yours, hers, its
Omitted letters
Apostrophes are used to show where one or more letters have been removed (a contraction).
don't = do not
didn't = did not
won't = will not
I'll = I will
we'll = we will / we shall
I'd = I would / I had
you'd = you would / you had
it's = it is
can't = cannot
who's = who is
Grammatical possession
Possession means that one word belongs to or is a part of another word. You can indicate possession by adding 's to the end of the word:
Zhi's finger
The car's horn
The president's suit
Note: you do not use an apostrophe when showing possession for a pronoun, so ‘it's’ does not mean “belonging to it”:
its = belonging to it
it's = it is
Grammatical possession and plural words
If a word is plural, that is, there is more than one of the word, you usually add an s without an apostrophe:
student > students
girl > girls
boy > boys
dog > dogs
If you want to indicate possession at the same time, however, it's incorrect to add both the s and the 's (you end up sounding like Gollum from The Lord of the Rings):
The students's flat
All girls's uniforms
All boys's uniforms
The dogs's bones
Instead, the second s is deleted, leaving the apostrophe on the end of the word:
The students' flat
All girls' uniforms
All boys' uniforms
The dogs' bones
Irregular plurals
For some words you indicate more than one of a word without adding an s
child > children
man > men
In that case, to show possession you only need to add 's, because there's no second s to delete:
The children's toys
The men's names
Plurals ending ies
Some plural words end with ies:
country > countries
baby > babies
story > stories
In that case, to show possession you only need to add an apostrophe at the end of the word:
The countries' leaders
The babies' prams
The stories' endings