One pair of commas can change which people you mean
Consider two sentences. ‘The students who submitted the report received feedback.’ ‘The students, who submitted the report, received feedback.’ Their words are nearly identical, but their meanings can differ. The first identifies a subset of students: the students who submitted the report. The second generally treats the students as an already identified group and adds that they submitted the report. In an examination, the grammatical issue is therefore not just whether a comma looks elegant. It is whether the punctuation preserves the writer’s intended claim.
This learner’s guide teaches relative clauses as meaning-making tools. It follows the integrated Vol 0312 fibre-link audit, where a report must distinguish what was tested from what was promised. It also builds on previous English lessons about pronoun reference and quantifiers. Rather than repeating a general grammar glossary, we will concentrate on one advanced performance task: decide whether a clause identifies a noun or merely adds information, and edit without quietly changing who, what or how many are being discussed.
The official examination context for G3 English
The first Singapore–Cambridge Secondary Education Certificate examination begins in 2027. The official SEAB 2027 G3 syllabus index identifies English Language as K300, replacing the former O-Level 1184 code. The K300 English Language syllabus sets out four components: Writing, Comprehension, Listening and Oral. Grammar accuracy, appropriate language and the ability to preserve meaning are useful across them, even though the illustrative sentences here are not taken from actual papers.
In the published K300 format, Paper 1 Writing lasts one hour 50 minutes, carries 70 marks and contributes 35% of the total; its Editing section carries 10 marks. Paper 2 Comprehension lasts one hour 50 minutes, carries 50 marks and also contributes 35%. Listening and Oral contribute 10% and 20% respectively. These details describe the 2027 syllabus, not all English courses or the assessment arrangements for other G3 subjects. Relative-clause choices can appear in editing practice and improve writing, but this guide does not claim that a particular relative-clause item must appear on the SEC examination.
First identify the noun being described
A relative clause adds information about a noun or noun phrase. In ‘The report that the team submitted was accurate,’ the clause ‘that the team submitted’ describes the report. In ‘The learner who checked the units found the error,’ the clause ‘who checked the units’ describes the learner. The identifying task is simple: ask which noun the clause attaches to. If you choose the wrong noun, the sentence can become confusing even when the individual words are grammatically possible.
The clause should sit close enough to its intended noun that the reference is clear. ‘The coordinator discussed the fibre with the technician who had failed the trial’ means the technician had failed the trial, not necessarily the fibre. If the writer means the fibre failed, write ‘The coordinator discussed the fibre that had failed the trial with the technician.’ The grammar is doing a factual job. It determines which person or thing is associated with a condition, action or property. Treat that job seriously before checking punctuation.
What a defining relative clause does
A defining relative clause, also called a restrictive relative clause, helps identify the person or thing being discussed. ‘The cables that were checked passed the inspection’ restricts the statement to the cables that were checked. It does not establish what happened to other cables. The clause is essential to the intended identification. In ordinary formal English, it is not enclosed by commas because removing it would change the reference or the claim.
Imagine three groups of fictional samples: checked, untested and awaiting repair. If a report says ‘The samples that were checked passed,’ it speaks about one defined set. Replace it with ‘The samples passed’ and it may suddenly appear to speak about all samples. The removal is not harmless. Editing a sentence requires you to consider whether a clause contributes to identifying the noun, not simply whether the sentence still sounds grammatical when the clause disappears.
What a non-defining relative clause does
A non-defining or non-restrictive relative clause adds information about an entity that is already identified. ‘The laboratory, which is on the second floor, opens at nine’ identifies a particular laboratory, then gives an extra fact about its location. Commas usually set off this supplementary information. Removing the clause leaves the intended referent clear: the same laboratory still opens at nine.
This distinction is sensitive to context. ‘The laboratory which is on the second floor opens at nine’ can be appropriate if several laboratories exist and the second-floor location identifies which one is meant. It is not automatically wrong merely because it lacks a comma. Conversely, when the writer and reader already know there is only one relevant laboratory, the non-defining version may be more natural. Ask what the reader needs in order to identify the noun. Punctuation follows the meaning rather than supplying it from nothing.
The difference is meaning, not just style
Some grammar exercises teach the rule as ‘commas for extra information, no commas for necessary information.’ That shorthand is useful but incomplete. Information can be interesting, relevant or important while still being grammatically non-defining. A clause may contain important background and yet not be needed to identify its noun. Another clause may seem minor but be essential to pick out the intended subset. The distinction concerns reference in the sentence, not how valuable the fact feels.
Consider ‘The employees who are trained may enter the room’ against ‘The employees, who are trained, may enter the room.’ In the first, training identifies those who may enter. In the second, the employees are already identified and training is presented as supplementary information about them. The punctuation changes what the reader may infer about eligibility. This is precisely why a grammar decision can affect safety, rules or fairness in a written notice.
When to use who, whom, whose, which and that
Who ordinarily refers to people and can function as the subject of a relative clause: ‘The teacher who explained the rule helped the class.’ Whom is a formal object form, as in ‘The mentor whom the team consulted,’ although many contemporary writers would naturally use ‘who’ in such a position or omit the object pronoun in a defining clause. Whose expresses possession or relation: ‘The student whose diagram was corrected tried again.’ It is not limited to people in all usage.
Which commonly refers to things or animals; that commonly introduces defining relative clauses about people or things, though style preferences vary. In standard formal English, a non-defining clause normally uses who, which or whose, not that: ‘The cable, which was tested, passed.’ The sentence ‘The cable, that was tested, passed’ should generally be corrected. Learn to choose by reference and clause function rather than imposing an absolute rule that which can never introduce a defining clause; it can.
The reliable test for who versus which
Ask what the antecedent is. If the antecedent is a person, who is the ordinary choice: ‘The volunteer who wrote the notice.’ If it is a device, which is natural: ‘The receiver which recorded the reading.’ In a defining clause about a thing, that is also often appropriate: ‘The receiver that recorded the reading.’ The choice need not be driven by a superstitious fear of one word; it should be grammatical and clear.
More complicated cases require care. A group or organisation can sometimes be treated as people or as an entity depending on variety and context. A pet may be referred to with who when the writer treats it personally. Examinations generally supply enough context to make the intended reference clear. Where the grammatical issue lies in whether the clause is defining, focus first on that distinction. Do not substitute a pronoun merely because you have memorised a blanket preference that ignores the sentence’s meaning.
Subject and object relative pronouns behave differently
In ‘The girl who won the award thanked her teacher,’ who is the subject of the relative clause, so dropping it yields an ungrammatical structure: ‘The girl won the award thanked her teacher.’ In ‘The award that the girl won was celebrated,’ that is the object of won; in a defining clause it can often be omitted: ‘The award the girl won was celebrated.’ The remainder is grammatical and keeps the same general identification.
This omission does not work in every relative clause. Non-defining clauses do not normally allow the relative pronoun to disappear in the same way: ‘The award, which the girl won, was celebrated’ cannot become ‘The award, the girl won, was celebrated’ with the same conventional relative-clause structure. A learner should identify the pronoun’s grammatical role and clause type before deciding whether an omission is permitted. Editing is not a guessing game where removing a word automatically makes a sentence more concise.
Why that is not used in ordinary non-defining clauses
Compare ‘My sister, who lives in Jurong, studies chemistry’ with ‘My sister that lives in Jurong studies chemistry.’ In the first version, the speaker may have already established which sister is meant; the location is supplementary. In the second, if the writer intends a defining distinction among several sisters, ‘who lives in Jurong’ is the clearer conventional choice for a person. Putting that between paired commas in the first structure is not standard formal usage.
With objects the pattern is even easier to see: ‘The new exhibit, which opened on Monday, was busy’ is a conventional non-defining relative clause; ‘The new exhibit, that opened on Monday, was busy’ should be repaired. A strong student does not automatically replace that with which everywhere. Sometimes the clause is defining and does not need commas. Sometimes the sentence is really two independent thoughts that would be clearer as separate sentences. Choose the least disruptive repair that preserves the intended facts.
Punctuation marks the boundary of the extra clause
A non-defining relative clause in the middle of a sentence is normally enclosed by two commas: ‘The main corridor, which the plan marks in blue, is accessible.’ If the clause comes at the end, a single preceding comma may be enough: ‘We selected the main corridor, which the plan marks in blue.’ The punctuation shows where the supplementary information begins and ends. Forgetting the second comma can cause the reader to merge unrelated parts of the sentence.
Consider ‘The coordinator, who reviewed the measurements approved the order.’ The comma after coordinator signals a non-defining clause, but the missing closing comma makes the structure stumble. The intended correction is ‘The coordinator, who reviewed the measurements, approved the order.’ It is important not to insert commas around an essential defining clause just because it is long. The decision still rests on whether the clause identifies the intended referent or adds information to one already known.
How one comma changes the reported result
A fictional project report says, ‘The receivers that were tested passed.’ Only the tested receivers are included in the claim. If a careless editor changes it to ‘The receivers, which were tested, passed,’ the revised wording can imply that the receivers under discussion were all tested and all passed. That is a stronger and potentially false statement. The comma is therefore not a decorative pause: it changes the information structure.
A good editor checks the dataset before touching punctuation. How many receivers were in the group? Were some never tested? Is the noun already uniquely identified? The decision cannot always be made from grammar alone because both sentences are grammatically possible under different facts. When the context is missing, avoid asserting one as universally correct. In examinations, use the surrounding passage and the intended referent to choose the appropriate interpretation.
How clauses protect the boundary of a scientific claim
Suppose a student writes, ‘The glass plates which had cracks were removed.’ This identifies cracked plates as the removed subset. In a science report, the restriction might matter because other plates remain in use. If someone changes the wording to ‘The glass plates, which had cracks, were removed,’ the sentence may suggest the already identified set of plates all had cracks. The grammar creates a different summary of the observation.
Science needs this precision because reports often concern only samples meeting a condition. Measured, heated, cooled, selected, exposed and untreated are not interchangeable categories. Before editing, ask whether the relative clause names a condition for inclusion in the measured set or provides background about a known item. The same question appears in graphs: which values belong to the denominator? Grammar and mathematical scope can support each other, and a mistaken comma can widen the apparent set.
The hidden role of the antecedent
The antecedent is the noun or noun phrase to which the relative pronoun refers. In ‘The proposal that the committee rejected was revised,’ the antecedent of that is proposal. In ‘The students whose calculations were checked remained confident,’ whose connects students to their calculations. This may seem elementary, but long sentences can contain several plausible antecedents, and a misplaced clause may attach to the wrong one.
Read ‘The students presented a model to the supervisor who was incomplete.’ The wording accidentally describes the supervisor as incomplete. The writer may mean that the model was incomplete. The repair is ‘The students presented an incomplete model to the supervisor,’ or ‘The students presented a model that was incomplete to the supervisor,’ depending on desired emphasis. The best edit moves the description next to the object it describes. Clear reference does more for accuracy than replacing a simple verb with a sophisticated one.
Relative clauses can carry time as well as identity
The tense of the relative clause affects meaning. ‘The students who have completed the task may leave’ identifies students whose completion is current and relevant. ‘The students who completed the task last week may leave’ refers to a specific past event. ‘The students who will complete the task may leave’ creates a future or predictive grouping that may not suit the intended rule. Grammar is not separate from chronology; it tells the reader which action qualifies a person.
In editing passages, check agreement and tense after confirming the antecedent. ‘The teacher who teaches science’ is different from ‘The teachers who teach science.’ The nearest noun is not always the grammatical subject of the relative clause; you need to see the clause’s internal structure. A correction that changes tense, number and clause type all at once may repair one error while introducing two others. Make the smallest change that restores the intended meaning.
Which clause contains the main message?
The main clause carries the central grammatical statement. In ‘The technician who checked the plan reported a discrepancy,’ the main clause is effectively ‘The technician reported a discrepancy,’ with the defining clause identifying the technician. In ‘The technician, who checked the plan, reported a discrepancy,’ the main clause is the same, but the added clause supplies supplementary information. This separation can help you find the subject and verb when a sentence looks crowded.
A useful editing technique is to temporarily bracket the relative clause while you check agreement. ‘The list of cables, which includes several alternatives, is on the desk.’ The main subject is list, so the main verb is is. The relative clause has its own subject which referring to list and its own verb includes. A student who blindly makes both verbs plural because cables is nearby will create disagreement. Locate the head noun before correcting the verbs.
Do not let the nearest plural noun control agreement
Consider ‘The collection of reports that was submitted yesterday is incomplete.’ The relative clause may refer to collection, so was can be appropriate. But ‘The reports that were submitted yesterday are incomplete’ requires plural verbs because reports is now the head noun being identified. The correct choice depends on the intended antecedent and sentence design, not a mechanical rule about using the nearest noun.
If a sentence is genuinely ambiguous, rewrite it rather than hoping agreement alone resolves the reference. ‘The report collection submitted yesterday is incomplete’ or ‘The submitted reports are incomplete’ may be clearer, depending on the facts. In a timed editing task, choose a concise correction that respects the original passage. In your own writing, avoid needless nesting of clauses that forces readers to work out which verb belongs to which noun.
Relative clauses and prepositions in natural English
An object relative can place its preposition near the end: ‘The topic that we talked about was difficult.’ A more formal version is ‘The topic about which we talked was difficult.’ Both can be grammatical. In conventional formal English, ‘the topic about that we talked’ is not the right construction. Choosing the longer form does not automatically make the sentence better; audience and register determine which is most readable.
For people, ‘The person to whom I wrote’ is formal, while ‘The person I wrote to’ is natural in many contexts. A school report need not sound archaic to be correct. The important decisions are that the preposition belongs to the intended verb, that the relative pronoun fits the construction and that the wording matches the task. Do not rewrite every sentence into a heavy phrase merely to demonstrate knowledge of whom.
When a relative clause is clearer as a new sentence
A sentence may contain several relatives, an apposition and a long introductory phrase. Even if technically grammatical, it may be tiring to read. Consider: ‘The committee, which reviewed the documents that had been sent by the group that collected the samples, made a decision.’ The reader has to track committee, documents, group and samples before reaching the main point. If the details matter, two or three sentences may serve the reader better.
For example: ‘The student group collected the samples and submitted its documents. The committee reviewed those documents and made a decision.’ This version gives each action a clear subject. In examination writing, clarity is not a contest to fit maximum information into one sentence. Relative clauses are useful when they compactly connect related ideas. When they create a chain of uncertain references, splitting the structure may preserve meaning more reliably than adding punctuation.
Compare defining clauses with participial phrases
‘The students who were waiting outside entered first’ can be shortened to ‘The students waiting outside entered first.’ The participial phrase still identifies the group of students. Such reductions can make prose tighter, but they should preserve the time and meaning intended by the original. ‘The students who had waited outside’ may emphasize an earlier completed action; reducing it to ‘the students waiting outside’ changes that time relationship.
The same risk appears with non-defining clauses. ‘The sensors, which were damaged during transport, were replaced’ can sometimes become ‘The sensors, damaged during transport, were replaced.’ The participial version still gives supplementary information, marked by commas. In school editing, it may not be necessary to shorten the sentence at all. Prefer the construction that makes the facts easiest to check. Concision is useful only if it keeps the intended information intact.
The danger of accidental generalisation
A defining clause may limit a general statement. ‘Students who revise their errors improve their chances of noticing repeated mistakes’ does not say that every student improves in the same way. ‘Students, who revise their errors, improve their chances…’ can present revision as a general property of the entire group, which may be inaccurate. The same change affects research summaries: ‘Measurements that used calibrated instruments were accepted’ is not equivalent to ‘Measurements, which used calibrated instruments, were accepted.’
When a source says some, selected, verified or tested, pay attention to whether the relative clause keeps the scope narrow. A common revision error is to simplify a careful claim into a universal one. The correction is not always to add the word some. It may be better to preserve the original defining clause and remove the misplaced commas. The guiding question is what set of people or items the sentence actually describes.
The danger of an unintended accusation
Relative clauses can change who is being criticised. ‘The workers who ignored the warning were questioned’ names only those who ignored it. ‘The workers, who ignored the warning, were questioned’ can accuse the entire already identified group of ignoring the warning. The difference matters in public communications, incident reports and any writing about real people. An editor should not broaden a claim because the longer version appears to read more smoothly.
This is also why a precise sentence can be more ethical than a dramatic one. Give readers only the information the evidence supports. If the source identifies two employees who missed a check, do not rewrite it as though everyone missed it. If it identifies an entire group and separately reports their action, a non-defining structure may be appropriate. In a G3 English examination, grammatical accuracy and meaning preservation reinforce each other; they are not competing goals.
Editing technique: identify the reference before the error
When you encounter a relative clause in an editing passage, first underline the noun it appears to describe. Ask whether the clause identifies a subset or adds supplementary information. Next decide whether commas belong. Only then check pronoun choice, subject–verb agreement, tense and sentence boundaries. This order avoids the common habit of replacing a word because it looks unfamiliar while leaving the intended reference unexamined.
Suppose the passage reads ‘The experiments, that were repeated three times, produced similar results.’ If experiments is an already identified set and repetition is supplementary information, ‘which’ is the conventional replacement for that in the comma-delimited clause. But if the intended meaning is to identify only the repeated experiments among several groups, a better repair is ‘The experiments that were repeated three times produced similar results,’ removing the commas. Context must decide. There is no responsible universal repair without the writer’s intended scope.
Editing technique: preserve the smallest meaningful change
A ten-mark editing section rewards accurate correction, not gratuitous rewriting. When a sentence needs a relative pronoun, change the incorrect form to the correct one. When a sentence needs agreement, repair the verb. If the intended clause is defining, avoid adding unnecessary commas. If it is non-defining, ensure both comma boundaries are correctly placed. Do not substitute a whole paragraph or new fact simply because another sentence sounds more elegant.
The same principle works in your own draft. A grammar review should protect what you have already established: time, identity, number, certainty and causation. Read the sentence before and after your edit. Ask whether the revised version still names the same people, objects and conditions. A successful edit is not merely a sentence that passes a grammar checker. It is a sentence that conveys the intended claim more accurately.
Worked case: three receiver sets
An imaginary science report describes twelve receivers. Five were tested, four were awaiting tests and three were damaged before testing. All five tested receivers passed. The sentence ‘The receivers that were tested passed’ accurately reports that subset. The sentence ‘The receivers passed’ is unsupported because seven were not shown to pass. The comma-delimited sentence ‘The receivers, which were tested, passed’ may wrongly suggest that the twelve receivers were all tested and all passed.
This example combines grammar with evidence. The numbers establish which conclusion is justified; the relative clause keeps the conclusion confined to the tested five. It also shows why the word all must be used with a named set. ‘All five tested receivers passed’ is correct on the fictional data; ‘All twelve receivers passed’ is not. The reader’s interpretation of the denominator can change with punctuation. Careful English is part of careful scientific reporting.
Worked case: a safety notice
A fictional notice reads, ‘Students, who have permission, may enter the equipment room.’ The writer intends that only students with permission may enter. The two commas can make permission sound like supplementary information about students already identified, rather than a necessary access condition. A clearer correction is ‘Students who have permission may enter the equipment room.’ The defining clause now selects the eligible group.
Would ‘Only students with permission may enter the equipment room’ be even clearer? Yes, for a public notice. The word only expresses the access restriction directly. An editing item may ask for a particular grammatical correction, while a writing task permits the clearest complete rewrite. The key is not to treat punctuation as a separate aesthetic problem; it controls the rule that the sentence communicates.
Worked case: a known laboratory
The audience knows there is exactly one Garden Laboratory in the fictional school. ‘The Garden Laboratory, which opened last year, is on the ground floor’ naturally adds opening date as supplementary information. The laboratory is already identified by its name. In contrast, ‘The laboratory which opened last year is on the ground floor’ can identify one among several laboratories by the year it opened.
The difference is not that the version without commas is always ungrammatical. It may be appropriate in the second context. In an assessment passage, use the surrounding details to decide whether the noun is already uniquely identified. If no context resolves the reference, explain the alternative readings when practising; in a real editing task, choose the reading best supported by the passage and the tested grammar feature.
Worked case: a reader can misread who did the work
Consider ‘The inspector questioned the student who wrote the report.’ The defining clause describes the student. The report’s authorship helps identify which student the inspector questioned. Now consider ‘The inspector, who wrote the report, questioned the student.’ The non-defining clause describes the inspector, and authorship has moved to a different person. Both sentences can be grammatical; they tell different stories.
If the source says the student wrote the report, the editor must not move the clause to inspector merely to shorten the sentence. If the source says the inspector wrote it, the first version would be inaccurate. A grammar question may require you to identify an antecedent even when no punctuation error exists. Read the sentence as a statement about people and actions before deciding whether a replacement preserves its meaning.
Worked case: an omitted object pronoun
The sentence ‘The route that the committee recommended has been approved’ is grammatical. In a defining clause, the object relative pronoun that can be omitted: ‘The route the committee recommended has been approved.’ The meaning remains essentially the same because route is the object of recommended and the subject of the main clause. By contrast, ‘The route that connects the two rooms has been approved’ cannot simply lose that, because that functions as the subject of connects.
A useful test is to remove the relative pronoun and read the result carefully. If you get ‘the route connects the two rooms has been approved,’ the structure contains two competing main verbs without a grammatical link. Restore the pronoun. Do not memorize the instruction ‘that is optional’ without the subject-versus-object distinction. Grammar rules become reliable when their conditions are visible.
Worked case: a non-defining clause with which
The original reads: ‘The new observation device, that was purchased last term, recorded a signal.’ If device is already identified and the purchase detail is supplementary, the standard formal correction is ‘The new observation device, which was purchased last term, recorded a signal.’ Both commas mark the added clause, and which is appropriate for the non-defining use. The main statement remains that the device recorded a signal.
What if the text instead intends to distinguish the device purchased last term from an older device? Then the clause may need to be defining: ‘The device that was purchased last term recorded a signal.’ Both grammatical solutions exist, but they suit different contexts. This is why a learner should practise meaning questions alongside isolated grammar corrections. A correct edit answers the actual passage’s need.
Worked case: agreement around a clause
A sentence reads, ‘The collection of models that were stored in the cabinet are incomplete.’ If the intended subject of the main clause is singular collection, the main verb should be is: ‘The collection of models that were stored in the cabinet is incomplete.’ The relative clause that were stored may describe plural models, so were can be right inside it. One sentence may legitimately contain a plural verb in the relative clause and a singular verb in the main clause.
Another wording, ‘The models that were stored in the cabinet are incomplete,’ makes both verbs plural because models is the head noun. Neither choice can be decided by blindly matching verbs to the nearest visible noun. Bracket the relative clause, locate the head noun and read the sentence in two layers. This method protects both agreement and reference.
Practice set: choose the sentence that means the intended thing
Task A: A school has many workshop groups. Only the groups that completed a safety briefing may enter. Choose ‘The groups that completed the safety briefing may enter,’ not ‘The groups, which completed the safety briefing, may enter.’ The defining clause expresses the eligibility condition. Task B: There is one named principal, already identified. The writer wants to add that the principal attended a seminar. Use ‘The principal, who attended a seminar, …’ if that detail is supplementary.
Task C: Four books were borrowed; two had damaged covers. Only the damaged books were repaired. ‘The books whose covers were damaged were repaired’ limits the action appropriately. Task D: A single uniquely named exhibition opened on Friday, and the date is an extra fact. ‘The exhibition, which opened on Friday, attracted visitors’ uses a non-defining clause. In each task, name the referent and the intended subset before choosing punctuation.
Practice set: repair the clause, not the whole story
Task E: ‘The report, that was reviewed yesterday, has been filed.’ If the report is already identified, change that to which and preserve the two commas. Task F: ‘The technician which measured the length was careful.’ If technician refers to a person, change which to who; no comma is required if the clause identifies the technician. Task G: ‘The learners who was invited arrived early.’ If learners is plural, change was to were within the clause.
Task H: ‘The device, which recorded the data was replaced.’ If the clause is supplementary, insert the missing second comma after data. Task I: ‘The samples the team analysed they were labelled.’ The sentence has competing structures; a clear repair is ‘The samples the team analysed were labelled.’ This last example removes the extra subject they. Each repair is small, but the reasoning depends on the structure. State the rule that supports it rather than merely copying the corrected line.
Practice set: explain when there are two possible answers
Task J: ‘The pupils who completed the assignment were praised.’ Can commas be inserted? It depends on the intended context. If only the pupils who completed it were praised, retain the defining clause without commas. If the writer refers to an already identified group of pupils, all of whom completed it, a non-defining clause with commas may be appropriate. The original wording alone may not settle the real-world facts.
Task K: ‘My brother who lives overseas called yesterday.’ If the writer has several brothers, the location may identify which one; without commas is reasonable. If the speaker has one brother already known to the reader, the version ‘My brother, who lives overseas, called yesterday’ can add his location as supplementary information. The lesson is not that all ambiguities can be eliminated by punctuation alone. Reference, shared context and the writer’s intended claim must be considered together.
A short composing exercise for scientific communication
Write three sentences about a fictional fibre demonstration. Sentence one should report a narrow observation: ‘The fibres that were tested transmitted a signal in the recorded trials.’ Sentence two should add supplementary background to a uniquely identified display: ‘The demonstration panel, which was prepared by the science club, described total internal reflection.’ Sentence three should limit the conclusion: ‘These observations do not prove that every possible fibre configuration will perform identically.’
Now review them for scope. The first sentence names the tested subset. The second uses paired commas because the panel is already identified. The third explicitly blocks unsupported generalisation. This is an exercise in English editing, not a second science article. It shows how grammar can protect the boundaries of the evidence used in an EMS report.
How to use reading comprehension to test a relative clause
A comprehension passage may describe a broad group, then make a statement about only a subset. A reader who ignores relative clauses can misunderstand the writer’s evidence. Suppose a passage says ‘Customers who ordered online received a refund.’ It does not necessarily say what happened to customers who bought items in person. If a question offers ‘All customers received a refund,’ the passage does not support it. The limiting clause matters to interpretation.
This complements Vol 0309 on non-narrative claims. There the reader separates observed facts from inference and advice. Here the reader also checks the grammar that identifies the population named in the fact. A small clause can determine whether an answer is supported or overbroad. Underlining the relative clause and its antecedent is often a faster comprehension check than rereading a long passage without a specific question in mind.
How to use relative clauses in situational writing
In a school proposal, a defining clause can specify the affected group: ‘Students who need additional reading support may register.’ A non-defining clause can supply background about an already named project: ‘The Reading Room, which opened this term, is available after school.’ These sentences do different jobs. The first controls eligibility; the second informs the audience about a named facility. If the eligibility condition is important, the writing should keep it plainly attached to the noun.
Do not rely on a relative clause when the message would be clearer with an explicit condition. ‘Only registered students may attend’ may be a better notice than a deeply nested sentence. The writer’s goal is to communicate required action, not demonstrate a large grammar vocabulary. The Secondary English Editing owner offers a wider route for correcting sentences while keeping meaning intact.
The link to earlier English foundations
The earlier Vol 0285 pronoun-reference guide asks readers to identify who or what a pronoun refers to. Relative clauses add another layer: they use relative pronouns to attach information to an antecedent, with comma choices that can change whether the information identifies a subset. Vol 0305 on quantifiers helps with words such as some, all and each, whose scope can become misleading if a relative clause is changed carelessly.
Students transitioning from primary school can use the PSLE English revision bridge and then return to these more demanding sentence structures. The habit is the same at every level: read what the sentence actually says before choosing an attractive correction. Grammar learning grows by layering more precise decisions onto reliable basic reading, not by abandoning the basics.
A practical ten-minute editing routine
Start with two minutes of identification: underline every relative clause and circle its antecedent in a short passage. Spend three minutes deciding which clauses define a subset and which add information about an already identified entity. Spend two minutes checking who, which, that, whose and omitted object pronouns. Spend two minutes verifying commas, tense and agreement. Use the last minute to reread the passage for meaning, including whether the edited wording has accidentally turned some into all.
The routine is deliberately small. It can be repeated with new texts and progressively harder references. One day use simple people-and-objects sentences; another day use scientific observations; another day use school rules. Do not spend twenty minutes arguing over a comma without the surrounding context. If two readings are genuinely possible, write down both, identify the facts that would choose between them and move on. That is a deeper skill than memorising isolated punctuation slogans.
A self-test before the actual examination
Can you explain the difference between ‘The results that were verified were published’ and ‘The results, which were verified, were published’? Can you recognize when an object relative pronoun may be omitted? Can you identify a clause whose antecedent is incorrectly placed? Can you keep the main verb in agreement with the correct head noun when a long relative clause intervenes? Can you rewrite a confusing sentence as two plain sentences without changing who did what?
If you can answer these questions, you are practising more than a single grammar point. You are learning to preserve evidence through language. On examination day, let the intended meaning guide the punctuation. Mark the antecedent, decide whether the clause identifies or adds, check pronoun choice and agreement, and read the entire sentence once more. The most reliable edit is the smallest accurate change that leaves the reader understanding the same facts more clearly.
