Possessive ‘S or OF? Learn which to use and why

English second language learners find this grammar point difficult. The reason is that possessive ‘s is a relatively infrequent form in written English, compared to more frequent forms such as plurals and past tense forms. Infrequent forms are harder to learn. Another reason that possession rules are difficult to learn is that we seem to have a choice between two possible forms: ‘s and of.

When should we use apostrophe + s (‘s) and when should we use a phrase with of? Many ESL/EFL textbooks provide this simple but unreliable rule:

Use ‘s for human nouns and of for nonhuman nouns.

according to The Grammar Book, Celce-Murcia and Larsen-Freeman (1999)

But this simple rule does not explain why it is more common to hear “The works of Shakespeare” or “Concordia University’s Applied Linguistic Department.” Shakespeare is a human and Concordia University is not.

Possessive Form Rules Based on Native Speaker Preferences

Celce-Murcia and Larsen-Freeman (1999) address this quandary with research conducted by Khampang (1973) which tested native speaker’s preferences of the two forms. Here are the rules.

RULE: Use the possessive ‘s for animate and of for inanimate nouns (not always reliable)

This is the rule that most people learn from their textbooks. “Animate” means alive. “Inanimate” means not alive.

My wife’s sister (animate and therefore correct)
The sister of my wife (incorrect)

The foot of the bed (inanimate and therefore correct)
The bed’s foot (incorrect)

Celce-Murcia and Larsen-Freeman (1999, p. 315)

The animate/inanimate rule is not always reliable because categories of animate and inanimate are flexible and subject to our impressions and desire to sound informal.

RULE: Use a possessive ‘s as the informal form

Use the possessive ‘s when you wish to sound less formal.

Shakespeare’s sonnets (informal)
The sonnets of Shakespeare (formal)

Celce-Murcia and Larsen-Freeman (1999, p. 315)

When you want to make an institution sound more human-like, use the possessive ‘s form.

Concordia’s Applied Linguistics Department is the best. (less formal)
The Applied Linguistics Department of Concordia University was founded… (more formal)

RULE: Use the possessive ‘s for inanimate nouns doing an action

When an inanimate thing acts like an animate being because it is performing an action, you should use the possessive ‘s form.

The train’s arrival was delayed. (preferred)
The arrival of the train was delayed. (not preferred)

Celce-Murcia and Larsen-Freeman (1999, p. 315)

RULE: Use the possessive ‘s for short double possessives

John’s sister’s boyfriend (preferred)
The boyfriend of John’s sister (not preferred)

Celce-Murcia and Larsen-Freeman (1999, p. 315)

RULE: Use the possessive of for longer noun phrases and double possessives

He is the son of the well-known politician. (preferred)
He is the well-known politician’s son. (not preferred)

Celce-Murcia and Larsen-Freeman (1999, p. 315)

What can I do for the husband of Dr. Smith’s daughter (preferred)
What can I do for Dr. Smith’s daughter’s husband? (not preferred)

Celce-Murcia and Larsen-Freeman (1999, p. 315)

Use the Virtual Writing Tutor grammar checker to check your writing for errors. For a list of common errors, try this page.