Checkpoint 8 · Grammar in Use

Conditionals: Zero, First, Second, Third and Mixed

How to form and use zero, first, second, third and mixed conditionals, the mistakes to avoid, and how if-sentences work in persuasive writing and stories, with practice and answers.

British & IGCSE › Checkpoint 8 › Checkpoint 8 English (Cambridge Lower Secondary 0861)

1. What a conditional sentence is

A conditional (if-sentence) has two parts: the if-clause, which gives the condition, and the main clause, which gives the result. If it rains (condition), the match will be cancelled (result).

The two clauses can go in either order. If the if-clause comes first, put a comma after it. If the main clause comes first, no comma is needed: If you are hungry, eat something. / Eat something if you are hungry.

Key words

Condition: what must happen first (the if part).
Result / consequence: what happens because of the condition.
Real condition: possible or true. Unreal (hypothetical) condition: imagined, unlikely or impossible.

2. The four main types at a glance

Type	Form	Use	Example
Zero	If + present, present	Facts and things that are always true	If you heat ice, it melts.
First	If + present, will + V1	Real, possible future situations. Warnings, promises	If we plant more trees, the town will be cooler.
Second	If + past simple, would + V1	Unreal or unlikely situations now or in the future. Dreams. Advice	If I were the mayor, I would ban cars from the centre.
Third	If + past perfect, would have + V3	Unreal past: regrets and missed chances	If we had left earlier, we would have caught the train.
Mixed	If + past perfect, would + V1 (or the reverse)	An unreal past with a result now (or a present fact with a past result)	If I had trained harder, I would be in the team now.

3. Each type in detail

Zero conditional: always true. Both verbs are in the present simple. You can usually replace if with when without changing the meaning: If / When plants don't get water, they die. Common in science and information texts.

First conditional: real future. The condition is possible. You can use can, may, might or an imperative in the main clause: If you finish early, you can leave. If you see Ali, tell him to call me. If the wind gets stronger, the ferry might stop.

Second conditional: imagined present or future. The past tense does not mean past time here: it shows that the situation is unreal. If I had a million pounds, I would build a library. (I don't have it.) Use could or might for ability or possibility: If we had more time, we could visit the oasis.

Third conditional: imagined past. Both parts are about a past that did not happen. If the driver had seen the sign, he would have stopped. (He didn't see it, so he didn't stop.) Use could have / might have for less certain results.

Mixed conditionals link different times. Past condition → present result: If she had taken the job in Dubai, she would be living there now. Present condition → past result: If I were more confident, I would have spoken at the meeting.

4. Other words that introduce conditions

Word	Meaning	Example
unless	if... not	Unless you hurry, you will miss the bus. (= If you don't hurry...)
as long as / provided that	only if	You can borrow my laptop as long as you return it tonight.
in case	because it might happen	Take an umbrella in case it rains.
If only / I wish	a strong wish or regret	If only I had listened! I wish I were taller.
Imagine if...	invites the reader to picture an unreal situation	Imagine if every street had its own garden.

5. Common mistakes

Wrong	Right	Why
If it will rain, we will stay inside.	If it rains, we will stay inside.	Never put will in the if-clause.
If I would have money, I would buy it.	If I had money, I would buy it.	No would in the if-clause. Use the past simple.
If I was you, I would apologise.	If I were you, I would apologise.	Use were with I / he / she in formal second conditionals.
If we would have left earlier, we would have caught it.	If we had left earlier, we would have caught it.	Third conditional: had + V3 in the if-clause.
If he had seen it, he would stopped.	If he had seen it, he would have stopped.	The main clause needs would have + V3.
Unless you don't study, you will fail.	Unless you study, you will fail.	Unless already means if not. No second negative.
If you press this button the door opens.	If you press this button, the door opens.	Comma after an if-clause that comes first.

6. How Checkpoint asks about conditionals

Conditionals are rarely asked about by name, but they are powerful in writing, and you may be asked about their effect in a persuasive or fiction text.

In persuasive writing, first conditionals make consequences sound real and urgent: If we ignore this problem, our beaches will disappear.
Second conditionals invite the reader to imagine a better (or worse) situation: If every family recycled, our streets would be cleaner.
In stories, third conditionals show regret: If only I had listened to her, none of this would have happened.
Zero conditionals state facts in information texts: If a camel finds water, it can drink more than 100 litres in a few minutes.

Exam-style example. If we do nothing, the old cinema will be knocked down. If we act now, it will become a home for young artists.

Question: How does the writer use if-sentences to persuade? Answer: The writer uses two first conditionals that show opposite results: doing nothing leads to loss, acting leads to something positive. This makes the choice seem simple and urgent and pushes the reader to act.

In your writing, use a first conditional to warn or promise in persuasive texts, a second conditional for imagination or advice (If I were you, I would...), and a third conditional for a character's regret at the end of a story.

الـ If بسهولة

ممنوع will أو would بعد If مباشرة.
حاجة حقيقية ممكن تحصل: If + مضارع ، will.
حاجة خيالية: If + ماضي ، would. وقول If I were مش If I was.
ندم على الماضي: If + had + التصريف التالت ، would have + التصريف التالت.

7. Practice

Complete with the right conditional: If I ______ (know) about the party, I would have come.
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had known (third conditional: unreal past).
Complete: If you mix blue and yellow, you ______ (get) green.
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get (zero conditional: a fact that is always true).
Complete: If it ______ (not rain) tomorrow, we will go to the beach.
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doesn't rain (first conditional: present simple in the if-clause, never won't rain).
Complete: If I ______ (be) the head teacher, I would make the break longer.
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were (second conditional: unreal situation).
Correct the mistake: If we will recycle more, the town will be cleaner.
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If we recycle more, the town will be cleaner. (no will in the if-clause).
Rewrite with unless: If you don't water the plants, they will die.
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Unless you water the plants, they will die.
Join as a third conditional: Ahmed didn't set his alarm. He missed the exam.
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If Ahmed had set his alarm, he wouldn't have missed the exam.
Write a mixed conditional: Sara didn't learn to swim as a child. She can't join the diving club now.
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If Sara had learnt to swim as a child, she could join the diving club now.
If we let the river die, our children will never see the birds that fill it today. Why is this an effective sentence in a persuasive speech?
Show answer
The first conditional presents a real, believable consequence. It links today's choice to the future of our children, which makes the reader feel responsible and creates urgency to act now.

Remember

No will or would straight after if. Real = present + will. Unreal = past + would. Regret = had + V3, would have + V3. Comma after a first if-clause.

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