Conditionals (Zero, First, Second, Third)

What Are Conditionals?

Conditionals are sentences with "if" that describe what happens (or would happen) under certain conditions. English has four main types:

Zero Conditional — General Truths

Structure: If + present simple, present simple

Used for things that are always true:

• If you heat water to 100°C, it boils.
• If it rains, the ground gets wet.
• If you don't sleep enough, you feel tired.

Tip: You can replace "if" with "when" in zero conditionals:

When you mix red and blue, you get purple.

First Conditional — Real Future Possibilities

Structure: If + present simple, will + base verb

Used for things that are likely to happen in the future:

• If it rains tomorrow, I will stay home.
• If you study hard, you will pass the exam.
• If she doesn't hurry, she will be late.

Variations

• If it rains, I might stay home. (less certain)
• If you finish early, you can leave. (permission)
• If it snows, don't drive. (imperative)

Common mistake: Do NOT use "will" in the if-clause:

• Wrong: If it will rain, I will stay home.
• Correct: If it rains, I will stay home.

Second Conditional — Unreal / Hypothetical Present

Structure: If + past simple, would + base verb

Used for imaginary or unlikely situations in the present/future:

• If I had a million dollars, I would travel the world.
• If I spoke perfect English, I would apply for that job.
• If she were president, she would change many things.

Special Rule: "Were" for All Subjects

In formal English, we use "were" (not "was") with all subjects in the second conditional:

• If I were rich... (formal/correct)
• If I was rich... (informal/common in speech)
• If he were here...

First vs. Second Conditional

Third Conditional — Unreal Past

Structure: If + past perfect, would have + past participle

Used for imaginary situations in the past (things that did NOT happen):

• If I had studied harder, I would have passed the exam. (But I didn't study, and I failed.)
• If she had left earlier, she wouldn't have missed the train. (But she left late and missed it.)
• If we had known about the party, we would have come. (But we didn't know.)

This conditional is about regrets and imagining different outcomes for past events.

Mixed Conditionals

Sometimes we mix second and third conditionals:

Past condition → Present result:

If I had accepted that job (in the past), I would be living in London (now).

Present condition → Past result:

If I spoke Chinese (generally), I would have understood the conversation (yesterday).

Quick Reference

Common Mistakes

Mistake 1: "Will" in the if-clause

• Wrong: If I will see him, I will tell him.
• Correct: If I see him, I will tell him.

Mistake 2: Confusing second and third conditionals

• Second (now): If I had more money, I would buy a car.
• Third (past): If I had had more money, I would have bought a car.

Mistake 3: Using "would" in both clauses

• Wrong: If I would have more time, I would learn piano.
• Correct: If I had more time, I would learn piano.

Practice Tips

1. Write about your wishes: "If I could live anywhere, I would live in..." (second conditional)
2. Think about past regrets: "If I had studied... I would have..." (third conditional)
3. Make predictions about tomorrow: "If it rains, I will..." (first conditional)
4. Listen for conditionals in songs, movies, and conversations. They are everywhere!