Relative Clauses (Identifying & Non-Identifying): Explicación Sencilla

Number 77 of 81 in B1 - PRE-INTERMEDIATE

New English word? Translate any word using double click.

¡Empezamos! ¿Cual es la diferencia entre Identifying (o ‘Defining’) y Non-identifying (o ‘non-defining’) relative clauses. Vamos a ver:

  • What is a koala?

A koala is an animal that lives in Australia.

  • What is a cardiologist?

A cardiologist is a doctor who specialises in heart conditions.

  • What’s the most beautiful village you’ve visited?

Taormina in Sicily is the most beautiful village I’ve ever visited.

Estas son Identifying Clauses, porque estas explicando lo que es algo. Ahora miramos unas ‘non-identifying clauses’:

  • The Queen, who is on an official visit to Kenya, is expected to return to Windsor this Saturday.
  • My car, which broke down yesterday, is at the mechanic’s.
  • The boy band 72-K, who are on their European tour, are performing tonight in Davingstock.

Estas son Non-Identifying clauses porque no explican quien es la Reina, ni lo que es un coche, ni quienes son 72-K. Sólo añaden una información, suponiendo que sabes de lo que se habla:

‘The Queen is the woman who is the Head of State in countries that have a monarchy.’ es identifying porque define lo que es una reina.

‘The Queen, who is on an official visit to Kenya, is expected to return to Windsor this Saturday.’ es non-identifying porque supone que ya sabes quien es la Reina. Simplemente te esta dando información.

OK! Ahora que sabemos la diferencia, vamos a mirar los detalles. No te preocupes. No es muy difícil:

Non-identifying clauses:

These are more formal sentences and are usually for writing, not speaking. The basic rule is:

  • Person, who ..information.., …information… (In Spanish: ‘que’)
  • Animal/Object, which ..information.., ..information… (In Spanish: ‘que’)
  • Person/Animal/Object, whose ..information.., ..information… (In Spanish: ‘cuyo’)

Basically, the non-identifying relative clause is a way of combining two sentences in one, without repeating the subject:

My brother lives in London. He is coming to visit next month = My brother, who is coming to visit next month, lives in London.

Our house is too small for us now. We bought it ten years ago = Our house, which we bought ten years ago, is too small for us now.

My boss divorced ten years ago. His children live with their grandparents = My boss, whose children live with their grandparents, divorced ten years ago.

If you are doing grammar exercises you have to look for the repetition. In the second example the repetition is ‘it’ (not ‘We’). If the repetition is a possessive (his, her, their, my, your…) then use ‘whose’ (=cuyo).

It isn’t usually important which part of the information you put first, but it’s usually better to put the second part of information first (behind the subject). Let’s repeat an example:

Our house is too small for us now. We bought it ten years ago:

  1. CORRECT: Our house, which we bought ten years ago, is too small for us now.
  2. INCORRECT: Our house, which is too small for us, we bought it ten years ago.

And the other way around?

We bought our house ten years ago. It is too small for us now:

  1. CORRECT: We bought our house, which is too small for us, ten years ago.
  2. INCORRECT: We bought our house ten years ago, which is too small for us.

Conclusion: Always use the second sentence first, although there is usually no difference.

The most common is ‘WHO’, ‘WHICH’ and ‘WHOSE’ between two commas, but there are other possibilities:

One comma:

  • We’re going to visit gran. She isn’t very well = We’re going to visit gran, who isn’t very well.


  • This is my university. Here I spent four years of my life = This is my university where I spent four years of my life.
  • My university is one of the best in the country. I had a good time there = My university, where I had a good time, is one of the best in the country.


When the repetition is an object (me, him, her, them..) you can use ‘whom’ instead of ‘who’. It is extremely formal, and almost non-existent in modern English:

  • I gave the answers to David. I help him a lot. =  I gave the answers to David, whom I help a lot.
  • Sarah is a great friend of mine. I owe her a big favour = Sarah, whom I owe a big favour, is a great friend of mine.

Personally, I never use it. I prefer ‘who’.

Exercise: Non-Defining Clauses

Try joining these sentences. Always use one or two commas! You’ll get the answers later. Use this notebook to write your provisional answers.

NOTEPAD: Write your answers
  1. Victoria is the most intelligent girl in the class. She wants to study at Cambridge University.
  2. Victoria comes from an important family. Her mother is related to the Duke of Kent.
  3. I saw Victoria at Brian’s house last weekend. She was with her friends.
  4. I saw Victoria at Brian’s house. It is in the centre of town.
  5. Brian’s house is the biggest I have ever seen. I went there for the first time last weekend.
  6. Brian is my sister’s boyfriend. She met him at Victoria’s birthday.

Identifying clauses:

Identifying clauses are not very complicated, but there are more options and exceptions. These are the most common structures:

  • This is the person who we met yesterday. (who = que / personas)
  • That’s the car which runs on vegetable oil. (which = que / animales o objetos)
  • Pinocchio was a doll whose nose grew when he told lies. (whose = cuyo)
  • A library is a place where you can borrow books. (donde / en lo cual)
  • A bank holiday is a day when shops and offices are closed. (cuando / en lo cual)

OK – no problem there. Remember that now we are defining things. I am trying to help you identify who I saw yesterday, or which car I am talking about. I am explaining who Pinocchio was, or what a library and a bank holiday is.

Two important points to remember:

1. You can replace who and which with that:

  • A mayor is a person who/that has political control over a town or city.
  • Kent is the county which/that is known as ‘The Garden of England’.

2. If the clause is followed by a subject (David, he, the man, we, Atletico Madrid….) you can omit it:

  • The mayor is the lady ( _ ) I spoke to you about last week. (who/that)
  • Kent is the county ( _ ) we’re going to visit this summer. (which/that)

That’s it! Now practise:

Exercise: Defining Clauses

Complete these sentences with 0 or 1 word. Use all possible options.

NOTEPAD: Write your answers
  1. A knife is something _____ cuts food.
  2. A knife is something _____ you use to cut food.
  3. A hospital is a place ______ you go when you are hurt or ill.
  4. Thanksgiving is a day in the USA ______  families get together to celebrate.
  5. A person _____ life I would like to have is my cousin Pat.
  6. A nurse is a person ______ works in a hospital.

Answers & More Exercises:

If you write your email address here you will get the answers – and more exercises – immediately. You will also receive a FREE E-BOOK and one newsletter every month (only one!) Click here for more information.