Level 1 — Foundation · Clauses & Paragraph Architecture
Lesson 11: Relative Clauses & Advanced Sentence Decoding
How an author layers a huge amount of information onto a single sentence using who, which, that, whose, where, and when — and a repeatable method for taking a 40-60 word sentence apart without losing the thread.
Learning Objectives
By the end of this lesson, you should be able to:
- Recognise all five relative words (who, which, that, whose, where, when) and the noun each one attaches to
- Tell a subject relative clause from an object relative clause by checking whether a verb or a noun follows the relative word
- Find a sentence's core by temporarily removing every relative clause and prepositional phrase, then reattaching them
- Tell a relative clause apart from a noun clause, and from a reason or time clause describing the same sentence
- Decode a long sentence with nested relative clauses using one repeatable, six-step method
Introduction
You now have a full toolkit: Subject → Verb → Object, phrase versus clause, prepositions, conjunctions, adjectives and adverbs, and pronoun reference. Today, all of it gets used together, to answer one question: how does an author pack so much information into a single sentence, and how do you take it apart?
What Is a Relative Clause?
A relative clause gives additional information about a noun. The common relative words: who, which, that, whose, where, when.
A relative clause attaches to one specific noun
The researcher who conducted the study published the results.
Main sentence: The researcher published the results. Additional information: who conducted the study — describing researcher.
WHO
who — for people
The manager who leads the team has extensive experience.
Main noun: manager. Relative clause: who leads the team — meaning, the manager that leads the team.
WHICH
which — for things, objects, ideas, studies, systems
The system which we developed reduced processing time.
Main noun: system. Relative clause: which we developed.
THAT
that can introduce a relative clause for either people or things:
The book that I bought is useful. · The researcher that conducted the study…
who is still the more natural choice for people in formal writing
Both are grammatically fine, but who reads more naturally when the head noun is a person, especially in formal English.
WHOSE
whose — possession or relationship
The researcher whose study changed the field became famous. — whose study? the researcher's.
The company whose employees receive regular training has better performance. — whose links company to employees as a relationship of belonging.
WHERE
where — a place or location
The city where I was born is beautiful.
Main noun: city. Relative clause: where I was born.
Technical writing uses it just as naturally: The environment where people work can affect productivity.
WHEN
when — a time or period
The year when the company was founded was important.
Main noun: year. Relative clause: when the company was founded.
There are periods when people experience significant stress.
The Basic Patterns
| Pattern | Example |
|---|---|
| noun + who + verb | The researcher who studied the problem… |
| noun + which + subject + verb | The system which the company developed… |
| noun + that + subject + verb | The method that researchers used… |
| noun + whose + noun + verb | The researcher whose work influenced psychology… |
| noun + where + subject + verb | The environment where people work… |
Subject Relative Clause vs. Object Relative Clause
Check what comes right after the relative word
A — subject relative clause: The researcher who conducted the study published the results.
who conducted — who is the subject, because who itself is the one doing the conducting.
B — object relative clause: The study that the researcher conducted was successful.
that the researcher conducted — that is the object, because inside this clause the subject is the researcher, the verb is conducted, and the study is what was conducted.
The Decoding Trick
What follows the relative word tells you its job
who conducted the study — who + verb → subject. which the researcher conducted — which + noun + verb → object.
Removing a Relative Clause to Find the Core
Set the relative clause aside first
The researcher who conducted the experiment in 2025 published the findings.
Remove the relative clause: The researcher published the findings. — that's the core. Then reattach: who conducted the experiment in 2025 — extra information about the researcher.
A Sentence With Two Relative Clauses
Each relative clause attaches to its own noun
The researcher who conducted the experiment in 2025 published the findings that challenged several widely accepted assumptions.
Core: The researcher published the findings.
who conducted the experiment in 2025 → describes researcher. that challenged several widely accepted assumptions → describes findings.
The researcher
↓ who conducted the experiment
published
↓
the findings
↓ that challenged several assumptions
Nested Relative Clauses
A relative clause can sit inside another relative clause's noun
The researcher who conducted the experiment that examined decision-making published the findings.
Main noun: researcher. Relative clause 1: who conducted the experiment… → describes researcher. Relative clause 2: that examined decision-making → describes experiment, which is itself inside relative clause 1.
researcher
↓ who conducted
experiment
↓ that examined
decision-making
A Method for Finding the Core
Six steps for any long, layered sentence
A Fully Worked Example
Every layer of a genuinely long sentence
The experienced manager who joined the company after completing an advanced business program carefully reviewed the financial report that the accounting department had prepared for the board.
Main subject: manager. Main verb: reviewed. Object: report.
Core: The manager reviewed the report.
Then the layers: who joined the company → manager · after completing an advanced business program → the timing/context of joining · that the accounting department had prepared → report · for the board → the purpose/recipient of that preparation.
Final meaning, with every layer back in place: An experienced manager, who had joined the company after completing an advanced business program, carefully reviewed the financial report that the accounting department had prepared for the board.
Finding the Main Verb Among Several Verb Forms
Only one verb belongs to the main subject
The sentence above contains four verb-related forms: joined, completing, reviewed, had prepared. Only reviewed is the main verb — because it's the one action performed directly by the main subject, manager. The rest belong to their own clauses or phrases.
Finite Verb vs. -ing Form
An -ing form is not automatically a main verb
The manager reviewed the report after completing the meeting.
Main verb: reviewed. completing is an -ing form inside a prepositional phrase — not the sentence's main, finite verb.
The manager who completed the meeting reviewed the report.
Here completed is the verb of the relative clause; the main verb is still reviewed.
Past Perfect Inside a Relative Clause
had prepared marks the earlier of two past events
The report that the team had prepared was submitted yesterday.
Main: The report was submitted yesterday. Relative clause: that the team had prepared — Past Perfect, because the preparation happened before the submission.
Commas and Two Kinds of Relative Clause
Essential vs. non-essential information
Essential: The employees who completed the training received certificates. — who completed the training narrows down exactly which employees; it's essential to identifying them.
Non-essential: John, who completed the training, received a certificate. — who completed the training is extra detail; John is already fully identified without it.
A Non-Essential Relative Clause in Practice
Commas often mark added, not identifying, information
The company, which was founded in 1995, now operates internationally.
Core: The company now operates internationally. Extra: which was founded in 1995.
A callback to Lesson 10's 'comma + which'
Recall from Lesson 10: The researchers repeated the experiment, which produced similar results. A comma before which can signal that it's commenting on the whole preceding event, not just the nearest noun — exactly the same pattern seen here.
Relative Clause vs. Noun Clause
A relative clause describes a noun; a noun clause acts as one
Relative clause: The book that I bought is useful. — that I bought describes book — which book?
Noun clause: I know that the book is useful. — that the book is useful isn't describing any noun; it's acting as the entire object of know.
Relative Clause vs. Adverb Clause
Three different jobs, one similar-looking shape
Relative: The researcher who conducted the study… — information about researcher.
Reason: The researcher stopped because the equipment failed. — why did they stop? Because the equipment failed.
Time: The researcher stopped when the equipment failed. — when did they stop? When the equipment failed.
Everything at Once
A single sentence carrying five different structures
The researchers who conducted the study in several hospitals found that patients who received regular support showed better outcomes because they were more likely to follow the recommended treatment.
Main subject: researchers. Relative clause: who conducted the study in several hospitals → describes researchers. Main verb: found. Noun clause (the object of found): that patients… showed better outcomes. Inside it, a second relative clause: who received regular support → describes patients. Reason clause: because they were more likely… — they → patients.
Researchers
↓ who conducted the study
found
↓
that patients
↓ who received regular support
showed better outcomes
↓ because they were more likely
to follow the treatment
Core: Researchers found that patients showed better outcomes. Every other piece layers information onto that backbone, one clause at a time.
This Is How You Read Difficult Books
The complete decoding engine, built across this course so far
A forty- or sixty-word sentence is never one impossible problem — it's this same short list, applied once.
Guided Reading Practice
Read the paragraph once, slowly, finding each sentence's backbone before its relative clauses.
Researchers who study human decision-making often examine the factors that influence the choices people make in situations where information is incomplete. Although individuals may believe that they are making rational decisions, the experiences they have had in the past can affect the way they interpret new information. This is particularly important when people are faced with complex problems that require them to evaluate several competing alternatives.
Sentence 1 — Core: Researchers examine factors. Extra: who study human decision-making → researchers · that influence the choices people make → factors · in situations where information is incomplete → situations.
Sentence 2 — Core: the experiences can affect the way. Full structure: Although individuals may believe… (contrast) · the experiences they have had in the past (relative clause on experiences) · can affect the way they interpret new information (the effect itself).
Sentence 3 — Core: This is important. Additional: particularly (emphasis) · when people are faced with complex problems (time/context) · that require them to evaluate several alternatives (describes problems).
Vocabulary in Context
conductverbformal
to carry out or organize an activity (পরিচালনা করা)
Often with conduct a study, conduct an audit, conduct an inspection
“The port authority will conduct an unannounced safety inspection of all bulk-handling sites this quarter.”
interpretverbformal
to explain or understand the meaning of something (ব্যাখ্যা করা/অর্থ বোঝা)
Often with interpret the data, interpret a clause, open to interpretation
“Lawyers disagreed on how to interpret the force majeure clause after the canal closure.”
evaluateverbformal
to judge the value or quality of something carefully (মূল্যায়ন করা)
Often with evaluate options, critically evaluate, evaluate performance
“Before awarding the contract, the panel evaluated each bidder on price, safety record, and delivery time.”
alternativenounneutral
one option among two or more possible choices (বিকল্প)
Often with viable alternative, consider alternatives, alternative to
“With the main berth closed for repairs, the agent proposed an alternative in the eastern terminal.”
outcomenounformal
the result or effect of an action or process (ফলাফল)
Often with positive outcome, likely outcome, outcome of
“The outcome of the arbitration was a partial refund of the demurrage charges.”
challengeverbformal
to question whether something is true, right, or legitimate (প্রশ্নবিদ্ধ করা)
Often with challenge an assumption, challenge a decision, openly challenge
“The union challenged the new roster, arguing that it breached the agreed rest-hour limits.”
assumptionnounformal
something accepted as true without being proven (অনুমান/ধারণা)
Often with underlying assumption, make an assumption, challenge an assumption
“The budget rests on the assumption that fuel prices will stay flat for the year.”
Chunks worth learning as whole units
conduct a study · examine a factor · influence a choice · make a decision · interpret information · evaluate alternatives · receive support · achieve an outcome · provide evidence · challenge an assumption · require someone to do something · be faced with a problem · be associated with · be influenced by
Especially useful: be faced with — People are often faced with difficult decisions.
Golden Rule
Golden Rule
However many clauses stack up in a sentence, it has exactly one backbone — find the main subject and main verb first, then attach every clause to whichever noun or idea it actually describes.
Never translate a long sentence word by word. Instead, work through it in order: What is the main subject? What is the main verb? What is the object or complement? Which information describes which noun? Which clause explains a reason, time, or condition? Only then: what is the complete meaning?
Lesson Summary
Today you combined everything this phase has taught you into a single decoding skill. You learned all five relative words and the pattern each one follows, how to tell a subject relative clause from an object relative clause, how commas distinguish essential from non-essential information, and how a relative clause differs from both a noun clause and a reason/time adverb clause. Most importantly, you practised finding the one backbone inside a genuinely long, nested sentence — the skill that makes a forty- or sixty-word sentence from a real book feel exactly as manageable as a short one.
Practice: Test What You've Learned
Work through every question yourself before checking anything.
Before you start
Do not use Google Translate or any other translation tool for these questions. If a sentence has several layers, write out each one separately rather than guessing the whole meaning at once.
Part A — Identify the Relative Clause
- The researcher who conducted the study published the results. — which words make up the relative clause?
Show answer
Who conducted the study is the relative clause, describing which researcher is meant. - The book that I bought yesterday explains human behavior. — which words make up the relative clause?
Show answer
That I bought yesterday is the relative clause, describing which book is meant. - The company whose employees receive regular training has better performance. — what relationship does whose show?
Show answer
Whose shows possession, linking company to employees — meaning the employees belonging to that company. - The city where the company was founded has changed significantly. — which noun is where connected to?
Show answer
Where is connected to city, identifying the place in which the company was founded.
Part B — Find the Core Sentence
- The experienced manager who joined the organization last year carefully reviewed the financial report that the accounting department had prepared. — what is the core sentence?
Show answer
The core sentence is: The manager reviewed the report. Everything else — who joined the organization last year and that the accounting department had prepared — is added detail describing manager and report. - Researchers who study human behavior often examine social factors that influence people's decisions. — what is the core sentence?
Show answer
The core sentence is: Researchers examine social factors. Who study human behavior describes researchers, and that influence people's decisions describes factors.
Part C — Identify the Main Verb
- The researcher who conducted the experiment analyzed the results carefully. — what is the main verb?
Show answer
Analyzed is the main verb — the action performed by the main subject, researcher. Conducted belongs to the relative clause who conducted the experiment. - The report that the team had prepared was submitted yesterday. — what is the main verb, and which clause does had prepared belong to?
Show answer
The main verb is was submitted. Had prepared belongs to the relative clause that the team had prepared, which describes report and uses the Past Perfect because the preparing happened before the submitting.
Part D — Full Decoding
- Identify every layer of this sentence: The researchers who conducted the experiment in several universities found that students who received regular feedback improved their performance significantly because they were able to identify their weaknesses more effectively. Find: the main subject, the main verb, the main object, the first relative clause, the noun clause, the second relative clause, the reason clause, who they refers to, and the core sentence.
Show answer
Main subject: researchers. Main verb: found. Main object: the noun clause that students who received regular feedback improved their performance significantly. First relative clause: who conducted the experiment in several universities, describing researchers. Noun clause: that students improved their performance significantly, functioning as the object of found. Second relative clause, nested inside the noun clause: who received regular feedback, describing students. Reason clause: because they were able to identify their weaknesses more effectively. They refers to students, not researchers. Core sentence: Researchers found that students improved their performance.
Part E — Deep Reading
- Explain this sentence in your own, simple English: People who regularly read complex material tend to develop stronger reading skills because they become more familiar with the structures and vocabulary that authors commonly use. Your explanation must show what who refers to, what because explains, what that refers to, and the sentence's main idea.
Show answer
Who refers to people, specifying which people — those who regularly read complex material. Because explains the reason their reading skills grow stronger: repeated exposure builds familiarity. That refers to the structures and vocabulary, specifying which ones — the kind authors commonly use. Main idea: reading complex material regularly makes you a stronger reader, because you get used to the sentence patterns and words that writers typically rely on.
Next: Lesson 12 — Conditionals & Hypothetical Thinking: if, unless, would, could, might, had, were — how to recognise when an author is discussing a possibility, a hypothetical situation, a prediction, or an alternative outcome.