Apostrophes are primarily used to show possession, though they have a number of other common uses, as well.
The primary use of the apostrophe is to indicate the possessive case.
To form a possessive with a singular noun, use an apostrophe followed by an s.
My aunt’s home is in Montana.
Our supervisor’s name is Joshua.
This is generally true even if the word itself ends with an s. Still add an apostrophe and s.
Have you seen Marcus’s report?
We reviewed James’s work yesterday.
On the other hand, some writers prefer to omit the s after the apostrophe whenever a word already ends in s or z. Though this guideline is easy to follow, it does not follow the norms of pronunciation, and it can therefore seem unnatural.
Last night we had dinner at Mr. Lewis’ home.
He loves to read about Jesus’ miracles.
Have you read Mr. Chavez’ report?
To create plural possessive nouns when the words end with an s, add just an apostrophe. Never add an apostrophe and an s to a plural noun that already ends in s.
The managers’s meeting will be tomorrow.
The board members’s recommendations were well received.
The managers’ meeting will be tomorrow.
The board members’ recommendations were well received.
For plural nouns that do not end with an s, add an apostrophe followed by an s. Do not write the apostrophe after the s.
Your childrens’ song was beautiful.
The gentlemens’ suggestions were outrageous.
Your children’s song was beautiful.
The gentlemen’s suggestions were outrageous.
For a more thorough discussion of possessives, see the article entitled “Possessive Nouns and Indefinite Pronouns.”
Use an apostrophe plus s to create the possessive case of indefinite pronouns. Indefinite pronouns are pronouns that do not refer to any particular person or thing, such as somebody, anybody, someone, anything, something, and so forth.
I found someone’s keys on the desk over there.
Have you heard anyone’s suggestions yet about what to do for the summer social?
For more information, see the article entitled “Indefinite Pronouns.”
To create the possessive form for the abbreviation of a singular noun, add an apostrophe plus s.
That CPA’s salary is twice what mine is.
I’m not sure I understand the MDRA’s mission.
Generally, do not use an apostrophe plus s to create the plural form of an abbreviation.
There were three CPA’s at the meeting.
Do you know how many students received their MBA’s last year?
Have you met any of the RN’s?
There were three CPAs at the meeting.
Do you know how many students received their MBAs last year?
Have you met any of the RNs?
However, if the abbreviation has both capital and lowercase letters or has two or more periods, then an apostrophe should be used to avoid misreading.
All of my brothers earned PhD’s
To make the plural possessive form of an abbreviation, add an apostrophe after the s only.
Have you heard the CPAs’ recommendations?
We understand the RNs’ want to change their schedules.
Plural Letters and Words
To pluralize a letter or a word used as a word, italicize the letter or word and use roman type for the final s. Generally, no apostrophe is used to make the plural form of a word or an uppercase letter.
Do you realize how many heretofores are in this affidavit?
I don’t appreciate all of the maybes I keep hearing.
Of course you should capitalize the Cs in The Carlton Company.
However, where the plural form of the capitalized letter might be misread if the apostrophe were omitted, then include it.
I think that there are two capital I’s in InterIndex.
When referring to letters used to represent scholastic grades, the letters are capitalized and left in roman type. An apostrophe is typically not necessary to create the plural form (though it is used after A so as not to confuse it with the word As).
He received three A’s, two Bs, and two Cs.
Our son received two I’s last semester.
An apostrophe generally is used for ease in reading, however, when creating the plural form of lowercase letters.
There are two t’s and two c’sin the word fettuccini.
Are those two e’s in that word?
To make the plural form of a number, add an s,without the apostrophe.
They like to skate figure 8s at the ice rink.
How many perfect 100s have you scored?
The apostrophe is also used to replace the missing letters in a contraction.
He said he couldn’t make it to the meeting this morning.
I haven’t seen her yet, but I’m sure she is around here somewhere.
Contractions are common in speech and informal writing, and many writers include them even in formal text to give the work a more conversational or relaxed tone. However, some readers disapprove of contractions in formal writing, so pay attention to the purpose of your document and the audience for whom it is intended.
When writing a contraction where the apostrophe comes at the very beginning of the word, make sure that an apostrophe, and not an opening single quotation mark (which is the default character that will be inserted by most word processors), is used.
‘Tis the best time of the year.
Filled with happiness and cheer.
’Tis the best time of the year.
Filled with happiness and cheer.
Such constructions are generally reserved for poetry and other forms of informal writing.
An apostrophe (again, not an opening single quote) is used to indicate the omission of the first two digits of a year.
His wife graduated two years before he did, in ‘75.
Do you remember the tornado of ‘05?
His wife graduated two years before he did, in ’75.
Do you remember the tornado of ’05?
However, do not omit the first two digits of the year if it might be unclear to readers which century is meant.
An apostrophe should not be used before the s when referring to the years of a particular decade.
He is definitely a child of the 1980s.
Her grandfather was a teenager during the 1950s.
Plural Form in Quotation Marks
The plural form of a word or phrase in quotations marks may look awkward, and thus the sentence should probably be revised to avoid this construct. If the plural form is retained, however, then an apostrophe plus s should be included within the quotation marks (never on the outside of the quotation marks).
With the state of marriage in this country, are there any “till death do us part’s” anymore?
With the state of marriage in this country, does anybody even make it to “till death do us part” anymore?
Sometimes writers mistakenly add an apostrophe where one does not belong. Following are instances where an apostrophe should not be used.
Do not use an apostrophe for nouns that are not possessive. This error sometimes occurs when a possessive pronoun appears in the sentence. However, a possessive pronoun does not necessarily mean that a nearby noun should also be in the possessive case. Rather, it depends on the grammatical function of the noun.
Their nephews’ all live in the Midwest.
Mr. Jenkins’s sons’, and their wives, visited here yesterday.
Our pets’ are like our surrogate children.
Their nephews all live in the Midwest.
Mr. Jenkins’s sons, and their wives, visited here yesterday.
Our pets are like our surrogate children.
Do not use an apostrophe for the possessive form of the personal pronouns its, whose, his, hers, ours, yours, or theirs. These words do not contain apostrophes, even though they are in the possessive case.
I did not know that their department had combined with our’s.
Liz said that their’s is a more relaxed working environment.
I did not know that their department had combined with ours.
Liz said that theirs is a more relaxed working environment.
The word it’s is the contraction of it is, and the word who’s is the contraction of who is. Do not confuse these two words with the possessive forms its and whose, which do not contain apostrophes despite being in the possessive case.
Every department has it’s own policies and procedures to handle such circumstances.
I don’t know who’s shirts these are that just arrived from the dry cleaner.
Every department has its own policies and procedures to handle such circumstances.
I don’t know whose shirts these are that just arrived from the dry cleaner.
Nor should apostrophes be used with the personal pronouns your, their, or theirs. Be careful not to confuse these words with the contraction you’re, they’re, and there’s.
What you’re colleagues said was inexcusable.
We have not heard they’re response yet.
Do you know which car is there’s?
What your colleagues said was inexcusable.
We have not heard their response yet.
Do you know which car is theirs?
Finally, present-tense verbs used with third-person singular subjects always end in s and do not ever have an apostrophe.
Our office boast’s some of the best talent in the nation.
Their yard look’s beautiful when all the flowers are in bloom.
Our office boasts some of the best talent in the nation.
Their yard looks beautiful when all the flowers are in bloom.