This module introduces possessives using an apostrophe + “s” in English. Possessives sometimes omit the “s,” which is covered here, too.
Plural vs. Possessive ‘S’
The misuse of the possessive -s is a grammatical error that plagues all sorts of writers. The possessive -s is most commonly misused when a writer confuses it with the plural form. Fortunately, the rules governing the usage of the possessive -s and the plural form are quite clear cut and logical.
Noun Plurals
The most common way to pluralize a noun is to simply add an -s at the end.
Hamburger (singular) becomes hamburgers (plural)
College (singular) becomes colleges (plural)
Nouns that end in a vowel followed by a -y take an -s in the plural.
Monkey (singular) becomes monkeys (plural)
Nouns that end in a consonant followed by a -y undergo a more dramatic change. First, the -y changes to an -ie and then an -s is added.
Baby (singular) becomes babies (plural)
Nouns that end in a sibilant (s, x, z, ch, sh) pluralize by adding an -es.
Church (singular) becomes churches (plural)
Nouns that end in an -is are replaced by -es in the plural.
Thesis (singular) becomes theses (plural)
Many nouns that end in -f pluralize by changing to -ves (but: roof – roofs, chief – chiefs).
Calf (singular) becomes calves (plural)
Nouns that end in -o preceded by a vowel usually pluralize by adding an -s. Nouns that end in -o preceded by a consonant usually pluralize with an -es. The nouns that do not follow this pattern are often words imported from other languages and take their plural form according to the rules of that language.
Soprano (singular) becomes sopranos (plural) – an exception to the consonant + -o rule (a borrowed word)
The Possessive
The possessive -s is used to show belonging: Kevin’s coat
But, belonging can be less obvious: A good night’s sleep
The possessive forms of nouns are formed by adding an apostrophe and in most cases the possessive -s. When in doubt about whether or not your phrase requires the possessive, turn it around and see if it breaks down into an “of the” statement.
The doctor’s stethoscope- The stethoscope of the doctor- Correct
Three days’ grace- The grace of three days- Correct
The doctors’ running the clinic- The running the clinic of the doctors – Incorrect
To place the apostrophe:
Add an ‘s to the singular forms of a noun, even if it ends in an -s.
The principal’s office
Mrs. Jones’s garden party
Add an ‘s to the plural forms of nouns that do not end in -s.
The children’s bedroom
Add an ‘ to the plural forms of nouns that end in -s.
The addicts’ support group
The seven Von Trapp kids’ singing nanny
Apostrophes and Possessive Pronouns
Apostrophes should not be used with possessive pronouns (yours, his, hers, its, ours, theirs). These pronouns do not need apostrophes because they inherently show possession.
Incorrect: his’ speech Correct: his speech
Incorrect: that bike is your’s Correct: that bike is yours
The most complicated possessive pronoun is “its”. Its and it’s do not serve the same grammatical function. It’s is a contraction for “it is” and its is the possessive pronoun that signifies “belonging to it”. Check if you’re using “it’s” correctly by asking yourself whether you could replace “it’s” with “it is” and still have your sentence make sense. Remember, you do not use an apostrophe with the other possessive pronouns in the third person singular, his and hers, so do not use it with its!
Using Its / It’s
| Correct | Incorrect |
| It’s true that the dog chases its tail. This sentence would be understood as follows: It is true that the dog chases its own tail. | Its true that the dog chases it’s tail. This sentence would be understood as follows: Belonging-to-it true that the dog chases it is tail. (This makes no sense.) |
Hint: If you can say “it is,” then use the contraction.
E.g. The dog wagged its tail makes no sense if you say “the dog wagged it is tail,” so don’t use an apostrophe.
Whereas
Its going to rain later today does make sense if you say “it is going to rain later today,” so use the apostrophe:
It’s going to rain later today.