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If Structures

Conditionals

Understand zero, first, second, third, and mixed conditional structures with real-world examples.

Conditionals on Grammartier spans A2–C2 levels, with 11 interactive lessons including Zero Conditional, Unless and Conditionals and First Conditional — each with clear explanations, real examples, and a quiz you can score instantly.

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11
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A1 → C2
CEFR coverage

Conditionals are "if" sentences — they describe a condition and its result. English has four main conditional types, plus mixed conditionals that combine different time frames, and choosing the right one comes down to one question: how real or likely is the situation? This page walks through all four types side by side, gives you a simple way to decide which one you need, and links down to a full interactive quiz for each.

By the end of this lesson, you will be able to:

  • Identify and form all four types of conditionals: zero, first, second, and third
  • Choose the correct conditional based on how real or likely a situation is
  • Use the if-clause and main-clause tenses correctly for each type
  • Recognise and avoid the most common conditional mistakes

Structure & Form

Conditional sentence structure reference showing if-clause tense mapped to main-clause tense for each type
How the if-clause tense maps to the main-clause form, for all 4 types.
Decision tree flowchart for choosing the correct English conditional sentence type
A quick way to decide which conditional you need.

How It's Used

Zero Conditional — General Truths

If + present simple, + present simple. Used for facts and things that are always true.

  • — If you heat ice, it melts.
  • — If you mix red and blue, you get purple.

First Conditional — Real Future Possibility

If + present simple, + will + base verb. Used for realistic future situations.

  • — If it rains, I will stay home.
  • — If you study hard, you will pass the exam.

Second Conditional — Hypothetical Present or Future

If + past simple, + would + base verb. Used for unlikely or imaginary situations now or in the future.

  • — If I won the lottery, I would travel the world.
  • — If I were you, I would apologize.

Third Conditional — Unreal Past

If + past perfect, + would have + past participle. Used for imagining a different past.

  • — If I had known, I would have come.
  • — If she had studied, she would have passed.

Mixed Conditionals — Combining Time Frames

Combine two different time frames — usually an unreal past cause with a present result, or a present condition with a past result.

  • — If I had studied medicine, I would be a doctor now.
  • — If I were more organised, I would have finished the project yesterday.

Exceptions to Watch For

Mixed conditionals combine time frames

Sometimes the if-clause and the result are in different time frames — for example, an unreal past cause with a present result: "If I had studied medicine, I would be a doctor now." These mixed forms are advanced but common in both spoken and written English.

'If I were' is standard, not just formal

In the second conditional, were is traditionally used for all subjects, including I/he/she/it — especially in the phrase "if I were you." "If I was" is common in casual speech, but many style guides still prefer were.

Common Mistakes

Common English conditional sentence mistakes and corrections
The most common conditional mistakes, corrected.

If I would have money, I would travel.

If I had money, I would travel.

Don't use would in the if-clause of a second conditional — the if-clause takes the past simple, and would only appears in the result.

If it will rain, I will stay home.

If it rains, I will stay home.

Don't use will in the if-clause of a first conditional — the if-clause takes the present simple, and will only appears in the result.

If I have known, I would have come.

If I had known, I would have come.

The third conditional's if-clause needs the past perfect (had + past participle), not the present perfect.

If you heated ice, it melts.

If you heat ice, it melts.

The zero conditional uses the present simple in both clauses — don't mix in a past tense for a general truth.

The four types of English conditionals: zero, first, second, and third, with formulas and examples
All 4 conditional types, from real to imaginary, at a glance.

The 4 Types of Conditionals at a Glance

How the if-clause and main-clause tenses map to each type, from real to imaginary.

FeatureZeroFirstSecondThird
If-clause tensePresent simplePresent simplePast simplePast perfect
Main-clause formPresent simplewill + base verbwould + base verbwould have + past participle
MeaningGeneral truthReal future possibilityHypothetical present or futureUnreal past
ExampleIf you heat ice, it melts.If it rains, I will stay home.If I won the lottery, I would travel.If I had known, I would have come.

Summary

Conditionals describe an "if" situation and its result. Use zero for facts, first for realistic futures, second for unlikely or imaginary present/future situations, and third for imagining a different past. The combination of tenses in the if-clause and the main clause determines the type of conditional and its meaning — including mixed conditionals, which pair tenses from two different types in one sentence.

Further reading: Cambridge Dictionary — Conditionals

Frequently Asked Questions

What's the easiest way to tell conditionals apart?

Look at the verb tense in the if-clause: present simple means zero or first, past simple means second, past perfect means third. Then check how real or likely the situation is.

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

Not in a standard first conditional — the if-clause uses the present simple (If it rains...), and will only appears in the main clause (...I will stay home).

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

Second conditional imagines an unreal present or future situation (If I won the lottery, I would travel). Third conditional imagines a different past that already happened and can't change (If I had won the lottery, I would have traveled).

Is 'if I was' or 'if I were' correct?

Both are used in practice. "If I were" is the traditional, more formal form (the subjunctive) and is expected in writing and exams. "If I was" is common in casual speech.

What are mixed conditionals?

Mixed conditionals combine two different time frames in one sentence, like an unreal past cause with a present result: "If I had studied medicine, I would be a doctor now."

Do all conditionals need the word 'if'?

No — unless, as long as, provided that, and in case can all introduce a conditional clause instead of if, though if is by far the most common.

All Conditional Lessons & Quizzes

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