Cleft Sentences

Cleft sentences are special structures used to add emphasis in English. Instead of saying "John broke the window," you can say "It was John who broke the window" to stress exactly who did it. This B1–B2 lesson covers cleft sentences exercises with answers — practise it-cleft, wh-cleft, and all-cleft structures online with multiple choice questions and printable PDF worksheets.

To master cleft sentences for adding emphasis, you need to understand 3 Cleft Types, 1 Purpose:

Type	Pattern	Example	Emphasis
It-cleft	It + is/was + FOCUS + who/that + clause	It was John who broke the window.	Flexible: subject, object, time, place, reason
Wh-cleft	What + clause + is/was + FOCUS	What I need is a holiday.	Highlights the complement
All-cleft	All + clause + is/was + FOCUS	All I want is some peace.	Limits to one thing only

All three types do the same job — they reorganise a sentence to put the spotlight on one element. The difference is which element you want to emphasise and how strongly you want to limit the focus. If you're already familiar with relative pronouns (who, which, that), you'll recognise some of the same words in cleft sentences — but they work differently here.

It-Cleft Basics: Emphasising with It is/was … who/that

The it-cleft is the most common cleft structure. It always begins with "It" and uses a simple formula:

It + is/was + focused element + who (people) / that (things) + rest of the clause

Who vs That: The Connector Rule

Focused Element	Connector	Example
A person	who	It was my mother who taught me how to cook.
A thing / concept	that	It was the storm that caused the power outage.

Tricky case — possessive nouns: When the focused element contains a person's name but refers to a thing, use "that":

It was the children's laughter that filled the room with joy. (Focus = laughter, not children)

Is vs Was: Matching the Tense

The verb in "It is/was" must match the time reference:

Context	Verb	Example
General truth / present	is	It is patience that separates good teachers from great ones.
Past event	was	It was the loud thunder that frightened the children last night.

Tip: Check the verb in the that-clause — if it's past tense ("frightened," "won"), use "was." If it's present tense ("separates," "keeps"), use "is."

Starting with "It"

Every it-cleft begins with It — never "There," "That," or "This":

✅ It was the fog that delayed the flight.
❌ There was the fog that delayed the flight.

Negative It-Clefts

Use wasn't / isn't to deny one element and emphasise another:

It wasn't the heat that bothered me — it was the humidity.
It wasn't Tom who broke the window — it was his brother.

⚠️ Don't Confuse: It-Cleft "that" vs Relative Clause "which"

In ordinary relative clauses, both "that" and "which" work for things: The car which/that I bought is red. But in it-cleft sentences, "that" is the standard connector — not "which":

✅ It was the exam that made students nervous.
❌ It was the exam which made students nervous.

This is a common trap because learners expect "which" to work the same way as in relative clauses.

👉 Practice It-Cleft Basics →

It-Cleft Variations: Time, Place and Reason

Beyond emphasising people and things, it-clefts can spotlight when, where, and why something happened. The structure stays the same — only the focused element changes.

Emphasising Time

Place a time expression after "It was" and keep the preposition that normally goes with it:

Preposition	Example
on + day	It was on Tuesday that the accident occurred.
in + year/month	It was in 2019 that she graduated from university.
during + period	It was during the summer that we decided to move abroad.
only recently	It is only recently that scientists have discovered the cause.

Special pattern — "not until": This emphasises how late something happened:

It was not until dawn that the rescuers found the missing hikers.

Emphasising Place

Use the appropriate preposition for the location:

Preposition	Example
in + city/country	It was in Paris that they first met.
at + specific place	It was at the station that I realised I had left my wallet.
on + street/surface	It was on this very street that the famous author grew up.

Emphasising Reason

Use "because" or "because of" to stress the cause:

It was because she was ill that she missed the exam.
It was because of the heavy rain that the match was cancelled.
It is for this reason that we must take action immediately.

Note: Only "because" works in the reason cleft pattern — not "since" or "as":

✅ It was because he works hard that he succeeds.
❌ It was since he works hard that he succeeds.

Contrastive Clefts: Not X but Y

Use "not … but" to contrast two elements:

It is not money but happiness that truly matters in life.
It was not John but Mary who won the prize.
It was his laziness, not bad luck, that cost him the job.

👉 Practice Time, Place & Reason Emphasis →

Wh-Cleft and All-Cleft Patterns

While it-clefts start with "It," wh-clefts (also called pseudo-clefts) start with "What," and all-clefts start with "All." These patterns place the emphasis at the end of the sentence.

What-Cleft (Pseudo-Cleft)

What + clause + is/was + focused element

The wh-clause acts as a noun clause (= "the thing that"), and the focused element comes last:

Pattern	Example	Meaning
What + clause + is/was + noun	What I need is a good night's sleep.	The thing I need = a good night's sleep
What + clause + was + noun	What really surprised me was her kindness.	The thing that surprised me = her kindness

Tense matching: The linking verb (is/was) must match the tense of the wh-clause:

What really annoys me is the noise. (present + present)
What surprised us was the CEO's resignation. (past + past)

⚠️ The Bare Infinitive Rule

When the wh-clause contains "do/does/did," the verb after "is/was" takes the bare infinitive (no "to," no past tense):

What he did was call the police. (NOT ~~called~~)
What she does every morning is go for a run. (NOT ~~goes~~)
What the team did next was develop a new strategy. (NOT ~~developed~~)

This is a major error hotzone — learners instinctively want to match tenses, but the "did … was" construction already carries the past meaning.

"What happened was (that)…"

This fixed pattern explains an event or situation:

What happened was that the flight was delayed by three hours.
What happened next was that the whole system crashed.

All-Cleft

All + clause + is/was + focused element

The all-cleft means "the only thing" — it restricts the focus to just one element:

Example	Meaning
All I want is some peace and quiet.	The only thing I want
All you need to do is sign here.	The only action required
All we could do was wait for the results.	The only option available

Note: After "All … do is," the following verb takes the bare infinitive: "All you need to do is sign here" (NOT ~~to sign~~).

Don't Confuse: "What" vs "All"

Both look similar, but they carry different weight:

Starter	Meaning	Example
What	The thing that (highlights)	What I need is a holiday. (= My need is a holiday)
All	The only thing (limits)	All I need is a holiday. (= A holiday is enough — nothing else)

"All" is more restrictive — it implies nothing else matters or is needed.

The-Cleft: The thing/person/reason/place …

These use a specific noun + relative word to create emphasis:

Noun + Relative	Example
The person who	The person who helped me was my neighbour.
The reason why	The reason why he resigned was the low salary.
The thing that	The thing that bothers me most is the constant noise.
The place where	The place where I feel most relaxed is my grandmother's garden.

Important: After "the thing," use "that" (not "what") — because the noun "the thing" already exists, you need a relative pronoun to modify it, not a free relative.

👉 Practice Wh-Cleft & All-Cleft →

Choosing the Right Cleft Structure

When all three cleft types can emphasise the same idea, how do you choose? Use this decision tree:

Quick Decision Guide

Step 1: What do you want to emphasise?

Element	Best Cleft Type	Example
A specific person	It-cleft	It was Sarah who suggested the idea.
A specific time/place/reason	It-cleft	It was in Paris that they met.
An action or quality (complement)	Wh-cleft	What the team needs is a strong leader.
The only thing needed	All-cleft	All that remains is to sign the contract.
An explanation of events	Wh-cleft	What happened was completely unexpected.

Step 2: Check the grammatical signals

If you see…	Choose…	Because…
___ was/is + NOUN + who/that + clause	It	It-cleft pattern
___ + verb + is/was + FOCUS (no "that" after blank)	What	Wh-cleft — "What" directly precedes a verb
___ + that + verb + is/was + FOCUS	All	All-cleft — "All" needs "that" as relative pronoun
___ was during/in/at/on + TIME/PLACE + that	It	It-cleft for time/place emphasis

Common Discrimination Points

"All" vs "What" before "that":

All that remains is to sign. ✅ ("that" follows directly)
~~What that~~ remains... ❌ ("What that" is ungrammatical)

"What" vs "It" before a verb:

What happened next was unexpected. ✅ (verb follows directly)
It happened next was... ❌ (not a valid it-cleft)

"It" with "was … who/that":

It was my brother who fixed the car. ✅
~~What~~ was my brother who... ❌

👉 Practice Mixed Cleft Sentences →

Reversed Wh-Clefts: Focus Fronting (C1)

In a standard wh-cleft, the focus comes at the end: "What I need is a holiday." A reversed wh-cleft flips this — the focus comes first:

FOCUS + is/was + what + clause

Standard Wh-Cleft	Reversed Wh-Cleft
What I need is a holiday.	A holiday is what I need.
What matters most is transparency.	Transparency is what matters most.
What led to his dismissal was his lack of honesty.	His lack of honesty was what led to his dismissal.

Why Reverse?

The reversed form is used when the focus element is already known or has been mentioned, and you want to confirm or reinforce it rather than introduce new information:

The board has been discussing the merger for months. The merger proposal is what the board has been debating. (confirming known information)
We keep hearing about budget cuts. Adequate funding is what this research project needs above all else. (reinforcing a point)

With a Demonstrative: "That is what…"

A common C1 pattern uses a dash and the demonstrative "that" to create a dramatic confirmatory statement:

Greater transparency in government spending — that is what voters have been demanding.
Financial stability — that is what every small business owner strives for.

This structure is particularly effective in speeches, opinion writing, and formal presentations.

Linking Verb Agreement

The linking verb must match the tense of the wh-clause, just as in standard wh-clefts:

Wh-Clause Tense	Linking Verb	Example
Present	is	Adequate funding is what this project needs.
Past	was	The professor's lack of transparency was what ultimately led to his dismissal.
Present perfect	is	That is what voters have been demanding.

Don't Confuse: Reversed Wh-Cleft vs Normal Sentence

A reversed wh-cleft looks like an ordinary sentence at first glance, but the "what" clause transforms it into an emphasis structure:

Ordinary Sentence	Reversed Wh-Cleft
This project needs adequate funding.	Adequate funding is what this project needs.
The storm caused all the damage.	The storm was what caused all the damage.

The "what" clause signals that this is a cleft sentence, not just a statement with a complement.

👉 Practice Advanced Cleft Sentences →

Inferential & If-Because Clefts (C1)

These advanced cleft patterns are used to correct misperceptions, explain causes, and clarify intentions — essential skills in formal and professional English.

Inferential Cleft: "It's not that… it's that…"

This pattern denies one interpretation and offers the real one:

It's not that + clause₁ ; it's (just) that + clause₂

Misperception Denied	Real Situation
It's not that I object to the plan;	it's just that the timeline seems unrealistic.
It's not that the candidate lacks experience;	it's that her communication skills need improvement.
It's not that I object to change;	it's that the proposed timeline is simply unachievable.

Key points:

The first clause uses "that" (not "because" or "why") to introduce what you're denying
The second clause mirrors with "it's (just) that" to introduce the real issue
Adding "just" softens the correction: "it's just that…"

Don't mix pairs: "It's not that…" pairs with "it's that…" — not "it's because…":

✅ It's not that I disagree; it's that we need more data.
❌ It's not because I disagree; it's that we need more data. (mismatched pair)

If-Because Cleft: "If X, it's because Y"

This pattern explains the cause of an observed situation:

If + situation, it is/was because + cause

Situation	Explanation
If employees are leaving in such large numbers,	it's because the company's management style is fundamentally flawed.
If the negotiations collapsed last month,	it was because neither party was prepared to make concessions.

Tense matching: Use "it's because" for present situations and "it was because" for past events.

Don't confuse cause and effect: "It's because" and "that's why" point in opposite directions:

It's because Y → Y is the cause (looking backward at the reason)
That's why Z → Z is the result (looking forward at the consequence)

Complex "Not Until" Patterns

You met the basic "not until" cleft at B2. At C1, these sentences become longer and more complex:

Complexity	Example
B2 (basic)	It was not until dawn that the rescuers found the hikers.
C1 (complex)	It was not until the full extent of the damage had been assessed that the insurance company agreed to pay the claim.
C1 (complex)	It was not until she read the contract in full that she realised how unfavourable the terms were.

The structure remains fixed as "It was not until… that…" — never "It had been not until" or "It has been not until."

At B1–B2, all cleft sentences use simple "is" or "was." At C1, you can combine modal perfect forms with cleft structures to express speculation about the past:

Certainty	Pattern	Example
Near certain	It must have been + focus + who/that	It must have been an insider who leaked the documents.
Possible	It may have been + focus + who/that	It may have been the managing director who authorised the merger.
Impossible	It can't have been + focus + who/that	It can't have been Sarah who sent the email — she was abroad.

Choosing the right modal: Match the strength of your modal to the strength of your evidence, just as with deduction and speculation:

Strong evidence (e.g., "no external hacker could have accessed that system") → must have been
Uncertainty (e.g., "though no one can prove it") → may have been