What is a conditional sentence in English?

A conditional sentence expresses a situation (the condition) and its possible result. It typically uses an if-clause to state the condition and a main clause to state what happens as a result. The tense combination in the two clauses signals how real, likely, or possible the situation is.

What's the difference between the first and second conditional?

The first conditional is used for real, possible situations in the future: If I finish early, I'll call you. The second conditional is used for unreal or unlikely situations in the present or future: If I had a million dollars, I would buy a house. The key difference is how probable the situation is — first conditional means genuinely possible; second conditional means imaginary or very unlikely.

How do you form the third conditional?

The third conditional uses the past perfect in the if-clause and 'would have + past participle' in the main clause: If she had left earlier, she would have caught the train. It is used to talk about situations in the past that did not happen, and their imagined consequences. It often expresses regret or a hypothetical outcome.

Can I use 'will' in the if-clause?

Generally, no — in standard conditional sentences, you do not use 'will' in the if-clause. Use the simple present instead: 'If it rains, I will stay home' is correct; 'If it will rain, I will stay home' is incorrect. There is one exception: when 'will' is used as a polite request rather than a future marker, it can appear in the if-clause.

What are mixed conditionals?

Mixed conditionals combine elements of different conditional types to express situations where the time frame of the condition and the result are different. The most common type uses a past perfect if-clause with a 'would + base verb' main clause: If I had taken that job offer, I would be living in New York now. This connects a past decision to a present consequence.

Are conditionals tested in English proficiency exams?

Yes — conditional sentences are one of the most frequently tested grammar areas in major English exams, including Cambridge B2 First (FCE), C1 Advanced (CAE), C2 Proficiency (CPE), IELTS, TOEFL, and PTE Academic. All four conditional types — plus mixed conditionals — can be tested at B2 and above.

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Conditional Exercises in English (All Levels)

Welcome to our complete collection of conditional exercises for ESL learners. Whether you're a beginner tackling the first conditional or an advanced learner working through mixed conditionals, you'll find free, interactive practice tests for every level. Each section includes a grammar review so you can study and practice in one place.

All exercises are free and interactive, with instant answer checking. Levels range from A1/A2 (Beginner) to B2/C1 (Advanced).

Quick Grammar Review: Conditional Sentences in English

What is a conditional sentence?

A conditional sentence describes a situation and its possible result. It typically contains two clauses: the if-clause (the condition) and the main clause (the result). The tense combination in each clause signals how real or likely the situation is.

If it rains, I will stay home. → real and possible future situation (1st conditional)

The four main conditional types

Type	If-clause	Main clause	Use	Example
Zero conditional	Simple present	Simple present	General truths, facts	If you heat water to 100°C, it boils.
First conditional	Simple present	will + base verb	Real, possible future situations	If she calls, I will answer.
Second conditional	Simple past	would + base verb	Unreal or unlikely present/future	If I won the lottery, I would travel the world.
Third conditional	Past perfect	would have + past participle	Unreal past situations; regrets	If she had studied, she would have passed.

Mixed conditionals

Mixed conditionals combine elements of the second and third conditional. They are used when the time frame of the if-clause and the main clause are different — for example, when a past condition has a present result, or vice versa.

Type	If-clause	Main clause	Example
Past condition → present result	Past perfect	would + base verb	If I had taken that job, I would be rich now.
Present condition → past result	Simple past	would have + past participle	If I were braver, I would have spoken up.

Key rules to remember

Never use "will" in the if-clause of a first conditional: ✗ If it will rain… → ✓ If it rains…
Use "were" (not "was") in formal second conditionals: If I were you, I would reconsider.
The if-clause can come first or second with no change in meaning — but a comma is used when it comes first: If she calls, I'll answer. / I'll answer if she calls.
"Could" and "might" can replace "would" in the main clause to express ability or possibility: If you practiced more, you could improve quickly.

Common mistakes to avoid

Wrong tense in the if-clause: ✗ If I will see him, I'll tell him. → ✓ If I see him, I'll tell him.
Using "would" in the if-clause: ✗ If I would have more time… → ✓ If I had more time…
Mixing up 2nd and 3rd conditional: ✗ If she studied harder, she would have passed. (mixed tenses without meaning to) → ✓ If she had studied harder, she would have passed. (3rd conditional)
Forgetting "have" in the third conditional: ✗ I would passed if… → ✓ I would have passed if…

🟢 Not sure where to start?
Beginners should start with The First Conditional 1 — it introduces the most common real-life conditional structure.
Intermediate learners should work through the first and second conditional exercises, then try First or Second Conditional? 1 to sharpen their contrast.
Advanced learners should head straight to The Third Conditional and Mixed Conditionals exercises.

All Conditional Exercises — Free & Interactive

(B) = Beginner (A1/A2) | (I) = Intermediate (B1/B2) | (A) = Advanced (C1/C2)

The First Conditional

The first conditional is used for real and possible future situations. Structure: If + simple present, will + base verb.

The First Conditional 1 B — Introduction to the first conditional with straightforward if/will sentences.
The First Conditional 2 B — More practice building first conditional sentences in context.
The First Conditional 3 B — Additional beginner-level first conditional practice.

The Second Conditional

The second conditional is used for unreal or unlikely present/future situations. Structure: If + simple past, would + base verb.

The Second Conditional 1 I — Practice forming hypothetical sentences about present and future situations.
The Second Conditional 2 I — Further practice with the second conditional in varied contexts.

First or Second Conditional?

These exercises focus on the key distinction between the first and second conditional — the difference between a real possibility and an unreal or unlikely situation.

First or second conditional? 1 I — Choose the correct conditional form based on context and meaning.
First or second conditional? 2 I — More contrast practice between real and unreal conditions.

The Third Conditional

The third conditional is used for unreal past situations — things that did not happen and their imagined consequences. Structure: If + past perfect, would have + past participle.

The Third Conditional 1 I/A — Introduction to the third conditional with emphasis on past regrets and hypothetical outcomes.
The Third Conditional 2 I/A — More practice forming and using third conditional sentences.

Mixed Conditionals

Mixed conditionals blend tenses across the if-clause and main clause to connect a past situation to a present result (or vice versa). These are more advanced structures typically found at B2-C1 level.

Conditional tenses (mixed) 1 I — Practice a range of conditional types in a single exercise.
Conditional tenses (mixed) 2 I — More mixed conditional practice with a variety of if-clause combinations.

Conditional or Future?

A common point of confusion for ESL learners is knowing when to use a conditional form versus a simple future or present tense. These exercises target that distinction directly.

Conditional or future? 1 I — Decide whether the sentence calls for a conditional or a future construction.
Conditional, future, or present? 1 I — A three-way contrast exercise covering conditional, future, and present tense choices.

Frequently Asked Questions About Conditional Sentences

What is a conditional sentence in English?: A conditional sentence expresses a situation (the condition) and its possible result. It typically uses an if-clause to state the condition and a main clause to state what happens as a result. For example: If it rains, we will cancel the picnic. The tense combination in the two clauses signals how real, likely, or possible the situation is.
What's the difference between the first and second conditional?: The first conditional is used for real, possible situations in the future: If I finish early, I'll call you. The second conditional is used for unreal or unlikely situations in the present or future: If I had a million dollars, I would buy a house. The key difference is how probable the situation is — first conditional = genuinely possible; second conditional = imaginary or very unlikely.
How do you form the third conditional?: The third conditional uses the past perfect in the if-clause and would have + past participle in the main clause: If she had left earlier, she would have caught the train. It is used to talk about situations in the past that did not happen, and their imagined consequences. It often expresses regret or a hypothetical outcome.
Can I use "will" in the if-clause?: Generally, no — in standard conditional sentences, you do not use will in the if-clause. Use the simple present instead: ✓ If it rains, I will stay home. ✗ If it will rain, I will stay home. There is one exception: when will is used as a polite request rather than a future marker, it can appear in the if-clause: If you will please take a seat, the doctor will see you shortly.
What are mixed conditionals?: Mixed conditionals combine elements of different conditional types to express situations where the time frame of the condition and the result are different. The most common type uses a past perfect if-clause (like the third conditional) with a would + base verb main clause (like the second conditional): If I had taken that job offer, I would be living in New York now. This connects a past decision to a present consequence.
Are conditionals tested in English proficiency exams?: Yes — conditional sentences are one of the most frequently tested grammar areas in major English exams, including Cambridge B2 First (FCE), C1 Advanced (CAE), C2 Proficiency (CPE), IELTS, TOEFL, and PTE Academic. They appear in sentence transformation tasks, gap fills, multiple choice grammar sections, and writing and speaking assessments. All four conditional types — plus mixed conditionals — can be tested at B2 and above.