Writing Center ECHO: The Apostrophe
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An educational resource of Division of Arts, English, and Humanities
ECHO: The Apostrophe
The apostrophe is used to do the following:
- show possession
- mark omissions in contracted words or numerals
- form plurals of letters, numerals, and words referred to as words.
Showing possession
The apostrophe can show the possessive case of nouns (Sam, Sally, car, horse, love, etc.) and indefinite pronouns (everyone, someone, anybody, nobody, etc.).
The possessive case of nouns and indefinite pronouns shows ownership or a similar relationship and may be indicated by the use of 's, by the apostrophe alone, or by an of-phrase.
everyone's friend | Â | or | Â | the friend of everyone |
the girls' laughter | Â | or | Â | the laughter of girls |
A possessive noun or pronoun may be related to a word (or word group) that precedes it or one that is clearly implied.
- Is that old, broken down Chevy Joe's or Linda's?
In other words, does the Chevy belong to Joe, or does it belong to Linda?
For singular nouns and indefinite pronouns, add 's
Frank's idea | Â | a week's work | Â | a nickel's worth |
anybody's guess | Â | someone's coat | Â | one's choices |
Option: If a singular noun ends in -s, add 's or only the apostrophe.
Keats's poetry | Â | or | Â | Keats' poetry |
a waitress's tips | Â | or | Â | a waitress' tips |
For plural nouns ending in -s, add only the apostrophe. For plurals not ending in -s, add 's.
 | girls' dresses | (dresses for girls) | |
 | babies' toes | (toes of babies) | |
but: | men's clothing | women's job | children's rights |
For word groups, add 's only to the last word.
my brother-in-law's house |
George Orwell, Jr.'s, reply |
the Secretary of Defense's idea |
To indicate individual ownership, add 's to each name.
- Frank's and June's dogs
(dogs belonging to Frank and dogs belonging to June)
- the doctor's and the dentist's offices
(an office belonging to the doctor and an office belonging to the dentist)
- the Joker's and the Penguin's henchmen
(henchmen belonging to the Joker and henchmen belonging to the Penguin)
Note
: To indicate joint ownership, add 's only to the last name.
- Frank and June's dog
- Batman and Robin's car
Marking omissions
Use an apostrophe to mark omissions in contracted words and omissions in dates.
cannot = can't | Â | he will = he'll | Â | I am = I'm |
class of 1991 = class of '91 | Â | they are = they're | ||
I will = I'll | Â | will not = won't |
Note
: Contractions in writing mirror speech. As a rule, they are avoided in formal writing, but they are common (and often preferable) both in informal writing and in dialogue.
Forming plurals
Use 's to form the plural of lowercase letters, of numbers, of abbreviations followed by periods, and of words referred to as words.
His b's look like 6's. | M.A.'s |
Her l's are illegible and her miss's look like mess's. | Ph.D.'s |
When needed to avoid confusion, use 's to form plurals of capital letters, of symbols, and of abbreviations not followed by periods. Either 's or s may be used to form such plurals as the following:
- the 1900's or the 1900s
- his 7's or his 7s
- two B's or two Bs.
NEVER use the apostrophe with the following pronouns: his, her, hers, its, our, ours, your, yours, their, theirs or whose.
Caution: Do not confuse its with it's, whose with who's or your with you're:
- Its motor is small. (the motor of it)
- It's a small motor. (It is a small motor.)
- Whose is that? (Who owns that?)
- Who's that? (Who is that?)
- Your hat, sir. (Here is your hat.)
- You're joking, right? (You are joking.)