Of

What is "of"?

Of is the most common preposition in English. It usually makes a link of meaning between two nouns or noun phrases. We will call them N₁ and N₂.

Of has many different meanings. It often has a meaning similar to the possessive form ('s), also called the "genitive".*

* There is also another way of expressing the meanings of of. Sometimes we use two nouns together: city centre = the centre of the city.

Ads example

1. Of often means "having", "owning", "possession"

Ex: N₁ of N₂ ↔ N₂ has N₁
- the owner of the car ↔ the car has an owner
- a friend of Sam ↔ Sam has a friend

Here of is an alternative form of possessive 's:
N₁ of N₂ ↔ N₂'s N₁
Ex: the uniform of a student ↔ a student's uniform

2. Of is used to link a part to the whole in: [N₁ of (part of) N₂]

- the top of the hill
- the roof of the house
- the handle of a knife
- the end of the week
- the front page of a book
- some parts of- the world
- a piece of cloth

3. Of is used to link a member to its group in: [N₁ of (member of) N₂]

- a Member of Parliament
- the last month of the year
- the youngest of the four boys

4. Of in quantity words: [N₁ of (amount of) N₂]

- a lot of noise / noises
- a large number of students
- a pair of shoes
- a litre of coke
- hundreds of men
- two kilograms of pork

Note: N₁ is often a pronoun such as all, some, much [see indefinite pronoun].

- all of the men
- a few of those nuts
- much of his advice
- some of the dust
- none of these animals

Ads example

5. Of is used after group noun like crowd, group, bunch: [N₁ of (group of) N₂]

- a bunch of flowers
- a flock of sheep
- a gang of criminals
- a group of students
- a range of mountains

Here N₂ describes members of the group.

6. Of in unit noun

Of follows nouns referring to containers or units of something: [N₁ of (contains) N₂].
- a bag of nails
- a bowl of rice
- a carton of milk
- a cup of tea
- a pot of coffee

7. The relation between N₁ and N₂ can be like the relation between verb and object

verb		object
N1	of	N2
... studies	... →	history

- the studies of history
- the invention of television
- your kind offer of help

8. The relation between N₁ and N₂ can be like the relation between verb and subject

verb		subject
N1	of	N2
roars	← ...	A lion

- the roar of a lion
- a death of Diana*
- the growth of industry

* This is an exception to Rule 12.2. below.

Ads example

9. The link between N₁ and N₂ can be like the link of the verb be

N1	of	N2
exciting	← is ←	The game

- the excitement of the game
- the difficulty of learning English
- the weakness of the pound

In the following examples, N₁ and N₂ refer to the same person or thing:

N1	of	N2
a city	← is ←	London

- the art of painting
- the city of London
- the job of being Prime Minister
- the problem of how to improve speaking skill

10. Of can link N₁ to the quality expressed by N₂

N1	of	N2
woman	→ has →	ability

- a man of courage
- a woman of ability
- a building of great beauty

11. There're many other ways in which of can link two nouns

- a difference of age
- a game of football
- one of the nicest people
- the people of the ancient Greece
- a ring of pure gold
- the name of my cat
- the sound of voices

Ads example

12. Forms of nouns which follow of

N1

of

N2

12.1. If N₂ is a pronoun, it must usually be a possessive pronoun*

N1	of	N2
a pen	of	mine*

* See 13 below about exceptions to 12.1., and about the change of meaning if we omit the 's of Jolie's.

12.2. If N₂ refers to a particular person, it is usually a possessive noun, that is, noun + 's

N1	of	N2
a friend	of	Sam('s)
a film / movie	of	Angelina Jolie('s)*
a guest	of	his mother('s)

* See 13 below about exceptions to 12.1., and about the change of meaning if we omit the 's of Jolie's.

12.3. If N₂ refers to an unspecified person - or is not a person - it cannot be a possessive noun, that is, it cannot have 's

N1	of	N2
the owner	of	a Lamborghini
the king	of	Thailand
the income	of	an average teacher
the heart	of	a dog
the color	of	a rose

Ads example

13. After nouns such as picture, drawing, video, movie, of can be followed by ordinary personal pronouns like him and me

- This is an old photograph of me.
- Susan does not like this painting of her. (= "this painting representing her")

Note:
1. A painting of her has a different meaning from her painting, or a painting of hers, which would usually mean "The / a painting that belongs to her or was painted by her".

2. Also, a film / movie of Angelina Jolie (= "about Angelina Jolie") is different from a film / movie of Angelina Jolie's (= "one made by her").

14. Of does not always come between two nouns; it also follows some adjectives and verbs

- I am afraid of dogs.
- You must be tired of watching television.
- The exploers died of hunger and cold. (= "because of")

15. Idioms

Of is used in many complex prepositions: because of, in need of, instead of, by way of, in favour of, in front of, in spite of, on the point of.

I hope this article helps. If you have any question, please leave a comment below.