A reduced relative clause is a shorter construction that modifies a noun without using the full structure of a finite relative clause. It commonly contains an -ing form, a past participle, or a to-infinitive.
Compare:
The passengers who are waiting near Gate 6 should prepare to board.
The passengers waiting near Gate 6 should prepare to board.
Both sentences identify the same passengers. In the second, waiting near Gate 6 modifies passengers without the relative pronoun who or the finite verb are.
These constructions are closely related to relative clauses. Modern grammar descriptions often analyze them as non-finite clauses modifying nouns, while some traditional grammar lessons use the term reduced relative clause more broadly.
Shortening a relative clause does not always preserve its meaning. The shorter version may remove information about time, possibility, or who performs an action.
Reduced Relative Clauses With -ing
An -ing construction can modify a noun that is understood to perform the action expressed by the verb.
Consider:
The electrician who is checking the wiring will return tomorrow.
The electrician checking the wiring will return tomorrow.
Both versions identify the electrician doing the work.
These noun-modifying structures are related to the participial constructions covered in the lesson on participial phrases.
Reduction Does Not Always Mean Deleting Who Is
Some relative clauses can be shortened by omitting a relative pronoun and a form of be.
The visitors who are waiting outside have already checked in.
The visitors waiting outside have already checked in.
But other reductions involve changing the verb form.
The families who live above the bakery often complain about the early deliveries.
The families living above the bakery often complain about the early deliveries.
The original relative clause contains live, not are living. The shorter construction uses living to describe the families by where they reside.
Does -ing Always Describe an Action Happening Now?
No. An -ing modifier does not have a fixed present-time meaning.
The students waiting outside the examination hall have been told to remain quiet.
Here, the waiting is taking place in the situation being described.
Compare:
People living near the airport often complain about aircraft noise.
This describes where people live, not an action happening at the moment of speaking.
An -ing modifier can also describe an activity in the past when the surrounding sentence establishes that time.
The passengers waiting on the platform that morning had no idea the train had been cancelled.
The surrounding sentence places the waiting in the past. The -ing form itself does not establish when the activity happened.
Reduced Relative Clauses With Past Participles
Past participle constructions commonly modify nouns that receive an action rather than perform it.
Compare:
The files that were recovered from the damaged laptop are incomplete.
The files recovered from the damaged laptop are incomplete.
The files were recovered by someone. They did not perform the recovery.
The same structure works with regular and irregular past participles.
The letters written during the expedition were discovered decades later.
Written is the irregular past participle of write.
Ongoing Passive Actions: Being + Past Participle
A passive action that is still in progress may require being + past participle.
The bridge that is being repaired is closed to traffic.
The bridge being repaired is closed to traffic.
Both describe repairs in progress.
Compare:
The bridge repaired last summer is closed again.
Being repaired describes work in progress. Repaired last summer identifies an earlier repair.
Past participles can also describe states or conditions rather than straightforward completed passive events.
The passengers seated near the emergency exit received additional instructions.
Here, seated near the emergency exit describes the passengers’ position.
Infinitive Relative Clauses
Some noun-modifying constructions contain a to-infinitive rather than a present or past participle.
These are often called infinitive relative clauses or infinitival relative constructions.
They are particularly common after expressions such as the first, the last, the next, and the only.
First, Last, Next, and Only
Amelia was the first passenger to board the aircraft.
The infinitive to board the aircraft modifies passenger. Amelia is understood to perform the boarding.
Compare:
Amelia was the first passenger who boarded the aircraft.
Both identify Amelia as the first passenger in the boarding sequence.
Other examples include:
Daniel was the only student to solve the final problem.
The next train to leave this platform will stop at Brighton.
The last person to arrive had to stand at the back.
An infinitive modifier does not independently establish a particular tense. The surrounding sentence helps determine when the action takes place.
For example, the next train to leave refers to an expected departure, while the last person to arrive can refer to an arrival in a completed sequence.
When the Noun Does Not Perform the Action
The noun modified by an infinitive is not always the person or thing performing the action.
Compare:
The first employee to sign the agreement received a confirmation email.
The employee signs the agreement.
Now consider:
There are three documents to sign before the meeting.
The documents do not perform the signing. Someone needs to sign them.
Another example:
We need a quiet place to discuss the proposal.
The place is where the discussion can happen. It is not the person or thing performing the discussion.
These infinitive constructions do not all come from deleting words in a full relative clause. The noun may perform the action, receive it, or identify the place or opportunity associated with it.
When a Relative Clause Cannot Be Shortened Naturally
A shorter construction may be grammatical but still change the original meaning.
The most important considerations are time, aspect, modal meaning, and whether the modifier sounds natural in the intended context.
When the Time Relationship Matters
Compare:
The scientist who discovered the new species received an award.
A proposed reduction might be:
The scientist discovering the new species received an award.
The second sentence is not a dependable equivalent. It does not present the completed discovery as clearly and sounds unnatural for this intended meaning.
That does not mean -ing modifiers cannot describe past activities. The problem is whether the shorter construction preserves the relevant event and its interpretation.
A past-participial construction may sometimes retain the essential relationship while removing an explicit tense distinction.
The employee who had been selected for the award thanked the committee.
The employee selected for the award thanked the committee.
The shorter construction identifies the selected employee naturally. Although it no longer expresses the past perfect directly, that distinction may not be important in this context.
When a Modal Meaning Would Be Lost
Consider:
The employees who might be selected for the award will be contacted tomorrow.
Compare:
The employees selected for the award will be contacted tomorrow.
The second sentence can suggest that the employees have already been selected.
The first preserves the uncertainty expressed by might.
A similar problem arises with:
The applicants who may qualify for financial assistance will receive further information.
Changing this to the applicants qualifying for financial assistance may suggest a more definite qualification status.
If possibility or uncertainty matters, keeping the full relative clause is clearer.
When the Verb Does Not Suit an -ing Modifier
Some verbs describe states rather than activities. They do not always work naturally in the same participial patterns as action verbs.
Compare:
The employees who know the safety procedures can help the new staff.
An attempted reduction would be:
The employees knowing the safety procedures can help the new staff.
That version sounds unnatural in this context.
The full relative clause is the better choice.
How to Check Whether a Reduction Preserves Meaning
The following comparisons show why a shorter construction should be judged by its meaning rather than its length.
| Full relative clause | Shorter construction | Assessment |
|---|---|---|
| The guests who are waiting outside | The guests waiting outside | Natural reduction |
| The houses that were damaged by the storm | The houses damaged by the storm | Natural passive reduction |
| The people who live near the railway | The people living near the railway | Natural in this context |
| The employees who might be selected | The employees selected | May lose the intended uncertainty |
| The scientist who discovered the species | The scientist discovering the species | Not a dependable equivalent for the completed discovery |
| The report that Maya submitted | The report Maya submitted | Relative-pronoun omission, not participial reduction |
A reduction is useful when it identifies the same noun and preserves the distinction the writer needs. When it changes an important meaning or sounds forced, the full clause is preferable.
Reduced Relative Clauses vs. Omitted Relative Pronouns
Removing an object relative pronoun is different from changing a finite relative clause into a non-finite modifier.
Omitting an Object Relative Pronoun
Consider:
The manuscript that Elena discovered was remarkably well preserved.
The object relative pronoun that can be omitted:
The manuscript Elena discovered was remarkably well preserved.
The shorter relative clause still contains the subject Elena and the finite verb discovered.
Compare:
The manuscript discovered during the excavation was remarkably well preserved.
Here, discovered during the excavation is a past-participial modifier, not a finite relative clause with an omitted object pronoun.
Why Subject and Object Relatives Matter
An object relative pronoun can often be omitted in a defining relative clause.
The film that we watched on Friday was surprisingly moving.
The film we watched on Friday was surprisingly moving.
But a subject relative pronoun cannot normally be omitted while keeping the same finite clause structure.
Correct: The singer who performed at the festival has released a new album.
Incorrect: The singer performed at the festival has released a new album.
The correct sentence uses who as the subject of performed.
Simply removing who does not produce a valid equivalent relative clause.
A different noun modifier may sometimes express a related meaning, but it must be assessed separately rather than treated as ordinary pronoun omission.
Position, Punctuation, and Clarity
Reduced relative clauses and related noun modifiers normally appear close to the nouns they describe.
Poor placement can make it unclear which noun is being modified.
Keep the Modifier Close to Its Noun
Consider:
The curator displayed photographs of the paintings damaged during the fire.
The position of damaged during the fire naturally connects it with paintings.
If the paintings were damaged, the intended meaning is:
The curator displayed photographs of the paintings that were damaged during the fire.
But suppose the paintings were unharmed and the photographs themselves were damaged. The sentence needs different wording:
The curator displayed the photographs damaged during the fire. They showed several paintings.
This makes clear that the photographs, rather than the paintings, were damaged.
When a sentence contains two plausible nouns, placing the modifier closer to its intended noun can prevent a misleading interpretation. Sometimes two shorter sentences are clearer than one complicated sentence.
Defining and Supplementary Information
Reduced relative constructions can identify which person or thing is being discussed.
The paintings displayed in the east gallery belong to private collectors.
The modifier helps identify the paintings.
They can also add supplementary information about something already identified.
The portrait, painted during the artist’s final years, was sold at auction.
The information between commas adds a detail about the portrait.
Compare the full version:
The portrait, which was painted during the artist’s final years, was sold at auction.
Both versions provide supplementary information rather than distinguishing one portrait from a larger group.
Commas depend on whether a modifier identifies the noun or adds information about something already identified. They are not automatically inserted or removed because a clause has been shortened.
Reduced Relative Clauses: Practice With Answers
1. Reduce an Active Relative Clause
Rewrite the sentence using an appropriate -ing construction.
The volunteers who are sorting the donated clothes will finish before lunch.
Possible answer:
The volunteers sorting the donated clothes will finish before lunch.
The volunteers perform the sorting, and the participial construction identifies them naturally.
2. Preserve an Ongoing Passive Meaning
Rewrite the sentence without losing the idea that the work is still in progress.
The apartments that are being renovated will be available next spring.
Possible answer:
The apartments being renovated will be available next spring.
Being renovated retains the ongoing passive meaning.
Using renovated alone would not express the ongoing work as clearly.
3. Interpret an Infinitive Modifier
Compare:
A. The first student to submit the form received a confirmation email.
B. The forms to submit are listed on the noticeboard.
Who performs the action in each construction?
Answer:
In A, the first student submits the form.
In B, the forms are the objects that someone needs to submit. The forms do not perform the action.
4. Decide Whether Reduction Preserves Meaning
Consider these two sentences:
A. The paintings that were restored last year are on display.
B. The paintings that might be restored next year are in storage.
Which sentence can be shortened naturally without losing an important distinction?
Answer:
Sentence A can be shortened:
The paintings restored last year are on display.
This preserves the reference to paintings restored in the previous year.
Sentence B should normally retain the full relative clause:
The paintings that might be restored next year are in storage.
The word might expresses possibility.
Changing the description to paintings restored next year would lose that uncertainty and produce an awkward interpretation of the future restoration.
5. Omitted Pronoun or Reduced Relative Clause?
Identify the construction in each sentence.
A. The article I mentioned yesterday has been updated.
B. The article published yesterday contains new information.
C. The article that I mentioned yesterday has been updated.
Answers:
A: A finite relative clause with an omitted object relative pronoun.
B: A past-participial noun modifier, commonly described as a reduced relative clause.
C: A finite relative clause with the object relative pronoun that expressed.
A and C use closely related structures. B uses a different grammatical construction.
6. Clarify Which Noun Is Modified
Consider:
The gallery displayed photographs of the sculptures damaged during the move.
Rewrite the sentence to express each meaning clearly.
Meaning A: The sculptures were damaged.
Possible answer:
The gallery displayed photographs of the sculptures that were damaged during the move.
Meaning B: The photographs were damaged.
Possible answer:
The gallery displayed the photographs damaged during the move. They showed the sculptures.
The revisions clarify whether the damage affected the sculptures or the photographs.
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