Conditionals
Conditionals are two-part sentences built from an if-clause and a result clause. English has four main types: zero (general truths), first (real future possibilities), second (unreal present or future), and third (unreal past). The verb forms in each clause signal how real or imaginary the speaker considers the situation.
The rule
How to form the four conditionals
Zero
Ifpresent simple, present simple
If you heat ice, it melts.
First
Ifpresent simple, willbase verb
If it rains tomorrow, we'll cancel the picnic.
Second
Ifpast simple, wouldbase verb
If I had more free time, I would learn the guitar.
Third
Ifpast perfect, would havepast participle
If she had studied medicine, she would have become a doctor.
Inside a sentence
IfIfyou heat ice,present simpleitsubjectmelts.present simple
IfIfit rains tomorrow,present simplewesubjectwillwillcancelbase verbthe picnic.
IfIfI had more free time,past simpleIsubjectwouldwouldlearnbase verbthe guitar.
- subject
- helping verb
- main verb
- key word
Which one do I need?
Which conditional?
Every answer at a glance
Zero conditional
The result follows every time, so both clauses take the present simple: if + present simple, present simple.
If demand rises and supply stays the same, prices go up.
First conditional
One realistic future situation: if + present simple, will + base verb. Never put will in the if-clause.
If I get a 7 in Writing, I'll apply for the master's course in Leeds.
Second conditional
An unreal or unlikely present or future: if + past simple, would + base verb. With be, formal English uses were: if I were you.
If every school taught coding, young people would find jobs more easily.
Third conditional
A different past that did not happen: if + past perfect, would have + past participle. Would have never goes in the if-clause.
If I had read the question more carefully, I would have scored higher.
Mixed: past condition, present result
An unreal past changes the present: if + past perfect, would + base verb, often with now or today.
If I had studied engineering, I would be earning far more now.
Mixed: present condition, past result
Something still true now explains a past result: if + past simple, would have + past participle.
If Omar spoke French, he would have got the job in Geneva.
How to use conditionals
What are conditional sentences?
A conditional sentence links a condition (the if-clause) to its result (the main clause). The if-clause can come first or second without changing the meaning; only the punctuation changes. When the if-clause opens the sentence, a comma separates the two halves; when the main clause opens, no comma is needed.
What makes conditionals powerful is that the verb forms carry the speaker's attitude. The same idea can be presented as a fact, a live possibility, a daydream or a rewritten past, purely through the choice of tenses. That is why examiners treat accurate conditionals as clear evidence of grammatical range.
- If you press this button, the machine stops.if-clause first, use a comma
- The machine stops if you press this button.main clause first, no comma
The four conditional types at a glance
Each type pairs a fixed tense in the if-clause with a fixed form in the result clause. Learn the four pairings as a table first; the meanings then fall into place, because the pattern is consistent: the further the verb forms move into the past, the less real the situation is.
Notice that the names zero to third are just labels for these pairings; nothing in the grammar itself counts. Many modern coursebooks simply call them real conditionals (zero and first) and unreal conditionals (second and third), which is often the more useful mental grouping.
| Type | Form | Use | Example |
|---|---|---|---|
| Zero | If + present simple, present simple | Facts and general truths | If you mix blue and yellow, you get green. |
| First | If + present simple, will + verb | Real future possibilities | If the traffic is bad tomorrow, I'll take the metro. |
| Second | If + past simple, would + verb | Unreal or unlikely present/future | If I won the lottery, I would travel across South America. |
| Third | If + past perfect, would have + past participle | Unreal past, imagining a different history | If we had left home earlier, we would have caught the train. |
- If a plant gets no light, it dies.zero, always true
- If the meeting overruns, I'll text you.first, a real possibility today
When do you use the zero and first conditionals?
The zero conditional states what is generally or scientifically true: the result follows the condition every time, so both clauses stay in the present simple. It is the natural form for rules, instructions and habits.
The first conditional narrows the focus to one specific future situation the speaker thinks is realistic. The if-clause stays in the present simple even though the meaning is future; the 'will' belongs only in the result clause. Imperatives also work as result clauses, which is common in advice and instructions.
- If water reaches 100 degrees, it boils.zero, a scientific fact
- If you finish the report today, your manager will be delighted.first, one real occasion
- If you get lost in the old town, just ask a shopkeeper for directions.imperative result clauses are fine
When do you use the second and third conditionals?
The second conditional imagines a present or future that is not real: the speaker either believes the situation is unlikely or knows it is impossible. The past simple in the if-clause does not refer to past time; it marks distance from reality. With the verb be, formal English uses 'were' for all persons: if I were, if she were.
The third conditional goes one step further and rewrites the past. Both the condition and the result are contrary to what actually happened, which makes it the natural grammar of regret, blame and relief. Because the past cannot be changed, the third conditional is pure speculation about an alternative history.
- If I lived closer to the office, I would cycle to work.unreal present, in reality I live far away
- If they had booked earlier, the flight would have been cheaper.unreal past, they booked late
- If I would live near the sea, I would swim every day.→ If I lived near the sea, no 'would' in the if-clause
Why is 'If I will' wrong?
The single most common conditional error worldwide is putting 'will' inside the if-clause. English marks future time only once, in the result clause; the if-clause takes the present simple even when it clearly refers to tomorrow. The same rule covers negative conditions: use 'if we don't', never 'if we won't'.
There is one narrow exception: 'will' can appear after 'if' when it means willingness in very polite requests: 'If you will take a seat, Dr Rahman will see you shortly.' This is formal, rare, and never needed in IELTS, so the safe rule for learners is simple: no will, would or won't directly after if.
- If I will see him at the conference, I will pass on your message.→ If I see him at the conference
- We'll miss the deadline if we won't hurry.→ if we don't hurry
- If everyone arrives on time, we'll start at nine sharp.present simple after if, will in the result
Unless, as long as and other words that replace 'if'
Several conjunctions can stand in for 'if' and follow exactly the same tense rules. 'Unless' means 'if… not' and already contains the negative, so the verb after it stays positive. 'As long as', 'provided that' and 'on condition that' present the condition as a strict requirement.
'In case' is the trap: it does not introduce a condition at all but a precaution taken beforehand. 'Take a jacket in case it gets cold' means take it now, before you know the weather, not 'take it if it gets cold'. Confusing the two changes the meaning of the sentence.
- Unless you register by Friday, you'll lose your place on the course.unless = if you don't register
- You can borrow my laptop as long as you return it before Monday.as long as = strict condition
- Take an umbrella in case it rains later.in case = preparation, not a condition
Common mistakes with conditionals
Find what is wrong in each one, then open it to check.
1If I will have time, I will help you move house.What's wrong? Show the fix
If I have time, I will help you move house.
The first conditional keeps the if-clause in the present simple even though the meaning is future; 'will' belongs only in the result clause.
2If she would study harder, she would pass the exam.What's wrong? Show the fix
If she studied harder, she would pass the exam.
The second conditional puts the past simple, never 'would', in the if-clause.
3If I was you, I would accept the offer.What's wrong? Show the fix
If I were you, I would accept the offer.
Formal and exam English uses the subjunctive 'were' for all persons in the second conditional; 'was' is informal.
4If we would have known about the strike, we would have driven.What's wrong? Show the fix
If we had known about the strike, we would have driven.
The third conditional if-clause takes the past perfect; 'would have' can never appear inside it.
5When I will arrive, I'll phone you.What's wrong? Show the fix
When I arrive, I'll phone you.
Time clauses with when, until, before and as soon as follow the same rule as if-clauses: present simple for future meaning.
6Unless you don't hurry, we'll be late.What's wrong? Show the fix
Unless you hurry, we'll be late.
'Unless' already means 'if not', so adding a second negative reverses the intended meaning.
Practise
Write your own
Write a sentence of your own with conditionals, about you, your studies or your town.
Conditionals in IELTS
Speaking
- Part 3 questions beginning 'What would happen if…?' are direct invitations to produce a full second conditional: 'If governments taxed sugary drinks, consumption would probably fall.' Examiners listen for that complete two-clause structure when deciding whether your range justifies Band 7.
- Drop a first conditional naturally into Part 1 answers about plans: 'If the weather stays nice this weekend, I'll probably go hiking.' Mixing real and unreal conditionals accurately across an interview is exactly the flexibility the Band 7 speaking descriptor describes.
Writing
- In Task 2, conditionals build consequence arguments: 'If public transport were free, car use would fall sharply.' Accurate conditionals across types 1 to 3 are core complex structures; essays that never move beyond simple sentences struggle to escape Band 6 for Grammatical Range.
- Use a zero conditional to state an accepted fact before you speculate: 'If children exercise daily, their concentration improves.' Following it with a second conditional proposal shows the tense contrast itself, which is an easy, low-risk way to demonstrate range in Task 2.