Reduced Relative Clauses

Reduced relative clauses are shortened versions of relative clauses. They are also known as reduced adjective clauses.

Relative clauses usually modify a noun or noun phrase in the sentence as in this example, where the word 'table' is being modified:

The table that he bought was for his kitchen

In this reduced clause, 'that' is no longer used:

The table he bought was for his kitchen

However, it is not always just a matter of omitting the relative pronoun. There are different reduced relative clause rules depending on the sentence involved.

Types of Reduced Relative Clauses

Reduced relative clauses are mainly created through the use of:

Present participle phrases
Past participle phrases
Past Participles
Prepositional Phrases
Adjectives and adjective phrases

We'll now look at each of these in turn.

Present Participle Phrases

if the relative pronoun is the subject of the relative clause, then the clause can be reduced to a present participle (verb + ing) phase or past participle (verb + ed) phrase.

If the verb is in the active voice, it gets reduced to a present participle phrase.

Any active tense can be changed to a present participle phrase e.g. present simple, past simple, present continuous, present perfect etc.

To do this you delete the relative pronoun and any auxiliary verbs if there are any, and use the present participle of the main verb. If it is a negative sentence, then we use 'not' at the beginning of the participle phrase.

Note that in these reduced relative clause examples there are a mix of active tenses:

Examples:

Affirmatives:

The people that exercised every day lost the most weight
The people exercising every day lost the most weight
There were many employees who were working very hard
There were many employees working very hard
The MPs, who have finally voted, are leaving parliament
The MPs, having finally voted, are leaving parliament

Negatives:

The people that did not exercise every day lost the least weight
The people not exercising every day lost the most weight

It is worth noting at this point that if a non-defining participle phrase refers to the subject of the independent clause, the phrase may be placed either immediately before or after the subject of that independent clause.

So in the case of this sentence, 'having finally voted' refers to the MPs in the independent clause (MPs are leaving parliament), so it can be placed in two positions:

Examples:

The MPs, who have finally voted, are leaving parliament
The MPs, having finally voted, are leaving parliament

OR:

Having finally voted, The MPs are leaving parliament

Past Participle Phrases

Simple Tenses

If the relative clause is in the passive voice and in a simple tense, then it can be reduced by deleting the relative pronoun and the verb 'to be', leaving you with the past participle.

If it is a negative, then you place 'not' at the beginning of the participle phrase.

Examples:

The new illness, which was discovered by a doctor in Nigeria, has not yet been named
The new illness, discovered by a doctor in Nigeria, has not yet been named
The silk, which is imported from Thailand, is worth a lot
The silk, imported from Thailand, is worth a lot

Continuous Tenses

If it is in the passive voice but is a continuous tense verb (present or past), then you delete the connecting word and 'to be', leaving you with 'being + past participle'.

You then have a continuous passive participle phrase.

Examples:

The building, which is being built by Kingston Developers, should be completed by May
The building, being built by Kingston Developers , should be completed by May

Perfect Tenses

If the clause in the passive perfect tense (present or past), then 'have' or 'had' is replaced by 'having'. So we end up with 'having + been' to make the reduced relative clause.

This is a perfect passive particle phrase:

Examples:

The new Town Hall, which has been designed by TMC Architects Ltd, is expected to receive several awards
The new Town Hall, having been designed by TMC Architects Ltd, is expected to receive several awards
Taiwan, which had been one of the first countries to close its borders, showed low numbers of Covid-19 deaths in March
Taiwan, having been one of the first countries to close its borders, showed low numbers of Covid-19 deaths in March

Again, if the non-defining participle phrase refers to the subject of the independent clause, the phrase may be placed either immediately before or after the subject of that independent clause:

Examples:

Having been designed by TMC Architects Ltd, the new Town Hall, is expected to receive several awards
Having been one of the first countries to close its borders, Taiwan showed low numbers of Covid-19 deaths in March

Choosing a Present or Past Participle Phrase

In the case of the perfect tenses, you can choose either a present or past participle, depending on what you wish to emphasise in the sentence.

When to Choose the Past participle

If you wish to emphasise the prior completion of the activity in the participle phrase, 'have' is changed to 'having', leaving you with 'having + past participle'.

You will then have formed a perfect active participle phrase:

Examples:

The students that have studied the hardest have the best results
The students having studied the hardest have the best results

So in the above example, it emphasised that the hard studying took place before the best results.

When to Choose the Present Participle

If you do not wish to emphasise in the participle phrase the prior completion of the activity, then it is more common to use the present participle.

In this case 'have' is omitted and the main verb of the relative clause is changed to the present participle.

Examples:

The students that have studied the hardest have the best results
The students studying the hardest have the best results

Past Participle

We've been looking at present and past participle phrases, but it should also be noted that we can in cases reduce relative clauses with just a past particle.

We can do this if the sentence has the verb 'to be' or 'to have' and only a past participle. In this case we can move the past participle to before the modified noun.

Examples:

The car, which had broken down, was by the edge of the road
The broken down car was by the edge of the road
The glass, which is stained, needs cleaning
The stained glass needs cleaning

Prepositional Phrases

If the relative pronoun is followed by a prepositional phrase, then this can be reduced.

Examples:

The book that is on the table is mine
The book on the table is mine
The house which is across the street is for sale
The house across the street is for sale
The man who is in the jacket is my cousin
The man in the jacket is my cousin

Adjective and Adjective Phrases

Adjectives

If the relative clause has only an adjective and the verb to be within it, then the adjective can be placed before the noun, and the relative pronoun (and verb 'to be') can be deleted:

Examples:

The boy who is oldest won the race
The oldest boy won the race
You can carry the box that is lightest
You can carry the lightest box
Let's go to the country which is the hottest
Let's go to the hottest country

Adjective Phrases

If there is a verb other than the verb to be (usually sense verbs such as smell, look, feel, sound etc), then we reduce it to an adjective phrase:

adjective + verb+ing

Examples:

The egg, which smelled foul, couldn't be eaten
The foul smelling egg couldn't be eaten
I played the song that sounded the best
I played the best sounding song
He always wears clothes that look expensive
He always wears expensive looking clothes

When do we use reduced relative clauses?

Reduced relative clauses can be used to make your writing more concise, so it is common to use them within formal or academic writing, though they can appear in any style of writing.

As the grammatically correct reduction of relative clauses is quite a difficult skill, it is something the examiner in the IELTS test will look out for when awarding a band 7 and above for grammatical range and accuracy.

Note though that this will NOT include reducing relative clauses to propositional phrases, adjective phrases, or adjectives because when you do this you are creating a more simple sentence. However, reduced relative clauses in the form of present and past participle phrases is seen as a higher level skill.

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