('s) / of

Possession with ’s and of

In English, we can show possession in two main ways:

• ’s (apostrophe + s)
• of

They often mean the same thing, but we use them in different situations.

1. Form of ’s

a) Singular nouns

Form: singular noun + ’s

• Tom’s computer (el ordenador de Tom)
• my sister’s room (la habitación de mi hermana)
• the dog’s tail (la cola del perro)

b) Plural nouns ending in -s

For regular plural nouns that already end in -s, we add only an apostrophe (’), not another s.

Form: regular plural noun (ending in -s) + ’

• my sisters’ room (la habitación de mis hermanas)
• the teachers’ meeting (la reunión de los profesores)
• the Carters’ house (la casa de los Carter)

Notice: there is no extra s after the apostrophe.

c) Irregular plurals (no final -s)

For irregular plural nouns that do not end in -s, we use ’s like a singular noun.

Form: irregular plural noun + ’s

• the children’s book (el libro de los niños)
• people’s opinions (las opiniones de la gente)

d) Two names together

When two people share the same thing, we put ’s only on the second name.

• Jack and Karen’s children (los hijos de Jack y Karen)
• my mom and dad’s car (el coche de mis padres)

2. When we use ’s

a) People

We usually use ’s to talk about possession with people.

• Tom’s computer (el ordenador de Tom)
• my sister’s room (la habitación de mi hermana)
• the students’ project (el proyecto de los estudiantes)

b) Animals

We also normally use ’s with animals.

• the dog’s bed (la cama del perro)
• the cat’s toys (los juguetes del gato)

c) Time expressions

We often use ’s with certain time expressions. The idea is “something that belongs to that time period”.

• yesterday’s newspaper (el periódico de ayer)
• next week’s meeting (la reunión de la semana que viene)
• a week’s holiday (una semana de vacaciones)
• ten minutes’ walk (un paseo de diez minutos / a diez minutos a pie)

Notice in ten minutes’ walk we have a plural noun (minutes) plus just an apostrophe.

3. When we use of

We normally use of to show possession with things and ideas, not people.

Form: the + noun + of + noun

• the temperature of the water (la temperatura del agua)
• the name of the book (el nombre del libro)
• the back of the car (la parte trasera del coche)
• the end of the movie (el final de la película)

In these examples, using ’s usually sounds strange or too informal:

• ✗ the water’s temperature (possible but less natural in many situations)

4. Organisations and places: ’s or of

With organisations and places, we can often use either ’s or of. Both are usually correct. Sometimes one just sounds more natural.

• the company’s success / the success of the company (el éxito de la empresa)
• the world’s population / the population of the world (la población del mundo)
• the city’s streets / the streets of the city (las calles de la ciudad)

In short, common expressions, ’s is very natural:

• the world’s problems (los problemas del mundo)
• the school’s principal (el director de la escuela)

In more formal or longer expressions, we often use of:

• the goals of the organization (los objetivos de la organización)
• the history of the university (la historia de la universidad)

5. Summary: ’s vs of

• Use ’s mainly for:
  • people: my friend’s car (el coche de mi amigo)
  • animals: the dog’s food (la comida del perro)
  • some time expressions: yesterday’s news (las noticias de ayer)
• Use only an apostrophe (’) after plural nouns that end in -s:
  • my parents’ house (la casa de mis padres)
  • the students’ books (los libros de los estudiantes)
• Use of mainly for:
  • things and ideas: the color of the sky (el color del cielo)
  • physical parts: the top of the page (la parte superior de la página)
• With organizations and places, both are often possible:
  • the