Punctuation Unit: Apostrophe Usage
Apostrophe Usage Study-Guide
The Apostrophe: An apostrophe (‘) is used for two main reasons when punctuating words in a
sentence, to show ownership or to form a contraction. There are four other ways in which an
apostrophe can be used as well: to indicate the plural form of numbers written in numerical form,
individual letters, and symbols; as a symbol for the word feet when using the standard
measurement system, as a symbol for the word degrees when writing geographical measurement
units, and to replace the century number when writing dates in numerical form.
Rule # 1: The most common use of the apostrophe is to indicate ownership or possession. A
possessive noun is a noun (person, animal, place, thing, or concept) that has been made to show
that something belongs to it. In order to change a singular noun (one of a kind) into its possessive
form, it is necessary to add an apostrophe (‘) and the letter “s” to the end of the word.
A. Singular Nouns: To show that something belongs to “one” person, animal, place, or thing, the
letter “s” should be added to the end of the word and an apostrophe should be placed between the
last letter of the word and the letter “s” that is added to the end of the word.
Examples:
Singular Noun
dog
book
California
boy
Possessive Form
dog’s
book’s
California’s
boy’s
Used in a Sentence
The dog’s food was placed in a bowl.
The book’s pages were torn.
California’s capital city is Sacramento.
That boy’s bicycle has a flat tire.
B. Plural Nouns: To show that something belongs to more than one person, animal, place, or thing,
when the letter “s” is added to the word to make it plural form (more than one), the apostrophe
should be placed after, or to the right of the letter “s” at the end of the word.
Examples:
Plural Noun
dogs
books
states
boys
Possessive Form
dogs’
books’
states’
boys’
Used in a Sentence
Five dogs’ tails were wagging at the same time.
Three books’ pages were damaged in the rain.
Ten states’ governors met at a political conference.
Two boys’ bicycles have flat tires.
Clarification (1): In a few cases, the singular (one of a kind) and plural (more than one of a kind)
forms of a word are spelled differently. In such cases, it is not necessary to add the letter “s” to the
end of the singular form of the word to make it into plural form. As a result, the apostrophe should
be placed between the last letter of the word and the letter “s” that is added to the end of the word
to show possession or ownership regardless of whether the word is written in singular or plural
form (see examples on next page). A number of nouns that are included under this rule are terms
that refer to people categories: man/men; woman/women; child/children; person/people.
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Punctuation Unit: Apostrophe Usage
Examples:
Singular Possessive Form of Noun
One man’s car was parked in the driveway.
One child’s toys were placed in a box.
One person’s job application was rejected.
One goose’s feathers were completely white.
Plural Possessive Form of Noun
Four men’s cars were parked in the driveway.
Several children’s toys were placed in a box.
Five people’s job applications were rejected.
Two geese’s feathers were both black and white.
Clarification (2): In some instances, the singular and plural forms of a word are spelled in exactly
the same way. In such cases, the letter “s” should be added to the word and an apostrophe should
be placed between the last letter of the word and the letter “s” that must be added to the end of the
word in the process of changing either the singular of plural form of the word into possessive form.
This is the same rule that is used for words that have separate spellings for singular and plural
form. In the process of studying this issue, you will notice that most words whose singular and
plural forms are spelled the same are the names of different kinds of animals.
List of Words Whose Singular and Plural Forms Can be Spelled in the Same Way: buffalo, deer,
fish, giraffe, salmon, sheep, swine, trout
Note: Notice that most of the words in which the singular and plural forms are spelled the same
identify the names of different kinds of animals.
Examples:
Singular Possessive Form of Noun
One deer’s antlers were longer than any others.
One sheep’s wool was very thick.
One trout’s mouth was damaged by a hook.
Plural Possessive Form of Noun
Four deer’s were longer than any others.
Ten sheep’s wool was very thick.
Several trout’s mouths were damaged by hooks.
Clarification (3): In cases where a compound word that is formed with the use of one or more
hyphens (-) is being changed to possessive form, the apostrophe is placed between the letter “s”
that is added to the end of the word to form the possessive case whether or not the compound word
is written in singular or plural form.
Examples:
Original Singular Form
Compound Word
brother-in-law
secretary-of-state
Original Plural Form
Compound Word
brothers-in-law
secretaries-of-state
Singular Possessive Form
brother-in-law’s
secretary-of-state’s
Plural Possessive Form
Used in a Sentence
I like my brother-in-law’s Ford Mustang.
I heard the secretary-of-state’s speech.
Used in a Sentence
brothers-in-law’s
secretaries-of-state’s
I like both of my brothers-in-law’s cars.
I heard both secretaries-of-state’s speeches.
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Punctuation Unit: Apostrophe Usage
C. People’s Names: The rules for showing the possessive form of people’s names are as follows:
(a) First Names: To show that something belongs to a person in cases where the person’s first name is
being used, simply add an apostrophe and the letter “s” to the end of the name.
Examples:
(1) Tom’s car is faster than Jim’s car.
(2) Karen’s room is always clean.
(3) Chris’s hat is brand new.
(b) Last Names: To show that something belongs to one person in cases where the person’s last name
is being used, add an apostrophe and the letter “s” to the word, even if the person’s name ends in the
letter “s”.
Examples:
(1) Mr. Smith’s car is faster than Mr. Garcia’s car.
(2) Mr. Jones’s car is faster than Mr. Thomas’s car.
Clarification: To show that something belongs to more than one person by the same name, first
change the word to its plural form and then place an apostrophe after (to the right of) the “s” at the
end of the name.
Example #1:
The Smiths’ house is located next to the Garcias’ house.
Clarification: In this case, the house belonging to more than one person by the name of Smith is
located next to the house belonging to more than one person by the name of Garcia.
Example #2:
The Joneses’ house is located next to the Nunezes’ house.
Clarification: In this case, the name Jones and Nunez end with the letter “s”. Therefore, by
following the rules for making words into plural form, the letters “es” were added to the names
Jones and Nunez to show that there is more than one person being referred to with the last name
Jones and the last name Nunez. The possessive case is formed by simply adding an apostrophe after
the “s” at the end of each name in plural form, just as is done with common nouns.
Rule #2: The second main way in which an apostrophe is used is to indicate that a letter or more
than one letter is missing in a contraction. A contraction is formed when two words are joined
together and one or more letters are taken out of one or both of the words being combined. When
forming a contraction, an apostrophe (‘) is used where the letter or letters of the original words have
been removed (see examples on next page).
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Punctuation Unit: Apostrophe Usage
Examples:
Original Words
a) I am
b) we have
c) they are
d) I have
Contraction of the Original Words
a) I’m
b) we’ve
c) they’re
d) I’ve
Clarification (a): Several commonly used contractions are formed using a combination of a verb
and the word “not”:
Examples:
Original Words
a) did not
b) can not
c) has not
d) have not
e) will not
Contraction of Main Word and “not”
a) didn’t
b) can’t
c) hasn’t
d) haven’t
e) won’t
Clarification (b): A number of commonly used contractions are formed using a combination of a
main word and the word “is”:
Examples:
Main Words
a) he is
b) she is
c) car is
d) dog is
e) man is
Contraction of Main Word and “is”
a) he’s
b) she’s
c) car’s
d) dog’s
e) man’s
Rule # 3: Generally speaking, an apostrophe should never be used to form the plural case of a word
(showing that there is more than one of a particular person place or thing). However, there
is an exception to the rule when creating the plural form of numbers written in numerical form,
the plural case of individual letters, and to create the plural case of different kinds of symbols:
Examples:
Number, Letter, Symbol
7
20
p
t


Plural Form Using an Apostrophe
7’s (more than one number 7 )
20’s (more than one number 20)
p’s (more than one letter p)
t’s (more than one letter t)
’s (more than one )
’s (more than one )
Clarification: It is also acceptable to simply add the letter “s” to the right side of a number, a
letter, or a symbol to create the plural form (7s, ts, s); however, it is often better to use
the apostrophe in order to avoid confusion. This is especially true when forming the plural case
of such letters as the letter “A”. By using the apostrophe between the letter and the “s” added
to it to create the plural form of the letter (A’s), it is clear that you mean two “A” letters instead of
the word “As”.
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Punctuation Unit: Apostrophe Usage
Rule # 4: An apostrophe can be used as a symbol to represent the term “feet” when numbers
written in numerical form instead of in word form.
Examples:
Word Form
(a) four feet
(b) twenty feet
(c) one hundred feet
Numerical and Symbol Form
(a) 4 ‘
(b) 20’
(c) 100’
Rule # 5: An apostrophe can be used as a symbol to represent the term “minutes” when
speaking of geographical measurement units (distances or locations on a map).
Examples:
Word Form
(a) thirty degrees and fourteen minutes
north latitude
(b) sixty-six degrees and thirty-three
minutes east longitude
Numerical and Symbol Form
30° 14’ north latitude
66º 33’ east longitude
Rule #6: Although it is not commonly used in this way, an apostrophe can be used as a
sumbol to represent the term “minutes” when speaking of time measurement units.
Examples:
Word Form
Numerical and Symbol Form
(c) The goal was scored at the eighty-seven
The goal was scored at the 87’ mark
minute mark of the game.
of the game.
(d) The test took forty-five minutes to complete. The test took 45’ to complete.
Rule # 7: An apostrophe can be used to replace the number representing the “century”
(the first two numbers at the beginning of the year) when writing dates.
Examples:
Entire Date
(a) 2005
(b) 1492
(c) June 15, 2075
(d) 6/23/2005
Date Written in Abbreviated Form
(a) ‘05
(b) ‘92
(c) June 15, ‘75
(d) 6/23/’05
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