How to Use Apostrophes
Posted by Jake Magnum | December 11, 2017 | Proper Punctuation
Apostrophes are used for two main purposes: to stand in the place of missing letters and to show possession.
It is rare to see a mistake when an apostrophe is used for the first of these two purposes. Words such as can’t, won’t, and shouldn’t are almost always used correctly by writers. However, when using apostrophes to show possession, some writers do make mistakes.
This article will help you ensure you are using apostrophes correctly in your writing and will also help you avoid misusing apostrophes.
Using apostrophes to indicate possession
Usually, using an apostrophe to indicate possession is straightforward. Phrases like the woman’s blouse and Jeff’s house come up all the time. Certain words can make writers second guess whether an apostrophe should be used, though.
When the noun ends with an s
Words that end with an s can be confusing when apostrophes are involved. Is it Charles’ or Charles’s? Is it boys’ or boys’s?
The rule is quite simple. If the noun is singular, you should add –‘s. If the noun is plural, you should add only the apostrophe.
Correct: This is Charles’s car.
Incorrect: This is Charles’ car.
Correct: This is the boys’ room.
Incorrect: This is the boys’s room.
Some authors prefer to omit the s after the apostrophe in such cases if either (i) the word ends with two s‘s or (ii) the word in question ends a sentence (the punctuation can look odd in this case).
Correct: This is Jess’s car.
Also correct: This is Jess’ car.
Correct: This car is Charles’s.
Also correct: This car is Charles’.
Also note that not all plural words take their possessive forms this way, though. Plural words that do not end in an s take the standard –‘s ending to become possessive.
Correct: Where are the men’s clothes?
Incorrect: Where are the mens’ clothes?
When two individuals possess something
Writers sometimes get confused when putting two entities together into the possessive form. Is it correct, for example, to write Phil and Betty’s or Phil’s and Betty’s?
Either could be correct depending on the context. If Phil and Betty own something together, Phil and Betty’s should be used. If Phil and Betty each possess their own thing, Phil’s and Betty’s should be used.
Correct: We are going to Phil and Betty’s house for dinner.
Incorrect: We are going to Phil’s and Betty’s house for dinner.
Correct: Phil’s and Betty’s houses are both in nice neighborhoods.
Incorrect: Phil and Betty’s houses are both in nice neighborhoods.1
Common misuses of the apostrophe
Do not use an apostrophe for non-possessive plural forms of words.
Some writers mistakenly place an apostrophe before an s when making a non-possessive word plural.
Correct: All students must ensure they are registered for the class.
Incorrect: All student’s must ensure they are registered for the class.
More commonly, writers mistakenly place an apostrophe before an s when writing the plural forms of numbers, abbreviations, and letters.
Correct: Personally, I think music from the 1970s is the best.
Incorrect: Personally, I think music from the 1970’s is the best.
Correct: I don’t buy DVDs anymore.
Incorrect: I don’t buy DVD’s anymore.
Correct: There were Bs written on the walls.
Incorrect: There were B’s written on the walls.
However, if a lowercase letter needs to be written, an apostrophe has to be used as it otherwise looks strange. Also, any uppercase A or I must take an -‘s ending to avoid having the reader see the word As or Is.
Correct: There were b’s written on the walls.
Incorrect: There were bs written on the walls.
Correct: There were A’s written on the walls.
Incorrect: There were As written on the walls.
Do not use an apostrophe for possessive pronouns.
So far, we have been discussing possessive forms of nouns. Possessive forms of pronouns never take an apostrophe, though. Some possessive pronouns, such and mine do not cause any problems, but possessive pronouns that end in an s can trick writers into improperly putting an apostrophe before the s.
Correct: This is yours.
Incorrect: This is your’s.
The pronoun it especially causes problems because both its and it’s are proper words (whereas, for instance, your’s in the example above is not actually a word in the English language). It does not take an apostrophe to become possessive.
Correct: I have to take the dog for its walk.
Incorrect: I have to take the dog for it’s walk.
1This sentence would be correct if Phil and Betty were co-owners of both houses. In the context that Phil and Betty each own their own house, this sentence is incorrect.
Hacker, D., & Sommers, N. (2012). A Canadian writer’s reference (5th ed.). Bedford/St. Martin’s: Boston.