Relative Adverbs

Relative adverbs are words that are used to start relative clauses. Relative pronouns also start relative clauses. The following question words can act as adverbs for this type of clause:




Identifying them can be confusing because they are not just used as relative adverbs. They also have other purposes. For example, they can be used to introduce questions:

  • Where are you going? 
  • When will you arrive?
  • Why did you do that?

They can also be used to make other types of clauses that are not relative clauses:

  • I don't know where she lives (noun clause)
  • I will leave when it gets light outside (adverbial clause) 

The key way to recognise relative adverbs is that they are introducing a relative clause and they come after the noun they are modifying:

The town (noun) where we usually go on holiday is in Northumberland

I will never forget the year (noun) when you proposed to me

I'm not sure of the reason (noun) why she left

So they are giving more information about the noun. We'll now take a look at these three adverbs with relative adverb examples. 

The Key Relative Adverbs


Where is an adverb of place, so it is used to refer to location. The place can be any kind of location, such as a country, city, geographical region, house, or shop.  

It replaces the preposition plus relative pronoun 'in which' or 'at which', which tend to be used only in formal contexts, such as academic writing or formal speech.

Take a look at these examples. In the first three, preposition + relative pronoun is used, but then the same sentences are presented with where used instead:

Preposition + Relative Pronoun (formal)

I've never been to the office in which my husband works

Is that the shop in which you bought your dress?

Paris, in which we met, is a beautiful city

Tell me about the city in which you grew up?

Where as Relative Adverb (informal)

I've never been to the office where my husband works

Is that the shop where you bought your dress?

Paris, where we met, is a beautiful city

Tell me about the city where you grew up?


When is an adverb of time, and so it is used to introduce a relative clause that relates to time.

So the noun the clause refers to will be a time generally or such things as a time of day, a day, a week, a year, or an era.

Again it replaces a preposition plus relative pronoun, in this case the words 'in which', 'at which', or 'on which', which are reserved for more formal contexts.

Preposition + Relative Pronoun (formal)

The 1970s is the decade in which heavy rock music dominated

I love our office parties, at which we get the chance to relax 

Tomorrow is the day on which I get my first pay check

When as Relative Adverb (informal)

The 1970s is the decade when heavy rock music dominated

I love our office parties, when we get the chance to relax

Tomorrow is the day when I get my first pay check


Why is an adverb of reason. The relative clause is thus relating to why something happened. 

In this case it is replacing 'for which': 

Preposition + Relative Pronoun (formal)

Do you know the reason for which he left?

The reason for which I turned down the job is that the pay was too low

There are many reasons for which people choose not to get married

Why as Relative Adverb (informal)

Do you know the reason why he left?

The reason why I turned down the job is that the pay was too low

There are many reasons why people choosenot to get married

We can leave out 'the reason' if the sentence still makes sense without it: 

Do you know why he left?

Defining and non-defining relative clauses

There are certain rules with relative adverbs related to whether the relative clause is defining or non-defining. 

Remind yourself of the difference between defining and non-defining relative clauses if you are not sure.

Defining relative clauses provide essential information about the noun being modified, and they cannot be omitted from the sentence. They do not have commas.

Non-Defining relative clauses provide extra or additional information. The additional information is separated by commas.

Where and when relative pronouns can be used in defining or non-defining relative clauses:

Where and When defining relative clauses

A chemists is a place where you buy medicine

I'm hoping for a time when we can be together again

Where and When non-defining relative clauses

The centre of the village, where you'll find the church and the gardens, is very beautiful

The summer, when the sun is shining, is always my favourite time of year.

Why, though, can only be used in defining relative clauses:

 defining relative clauses

I don't understand the reason why they failed the exam

Can you tell me why you are late?

More on Relative Clauses:

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