The 4 Types of Conditional Sentences, Made Simple

What a conditional sentence does

A conditional sentence has an "if" clause and a result clause. It talks about what happens (or would happen) under a certain condition. English has four main types, each tied to how real or likely the situation is.

Zero Conditional: general truths

Structure: If + present simple, present simple

• If you heat water to 100°C, it boils.

Use this for facts that are always true — science, routines, rules.

First Conditional: real future possibility

Structure: If + present simple, will + base verb

• If it rains tomorrow, I will stay home.

Use this for realistic future situations — things that could genuinely happen.

Second Conditional: unreal or unlikely present/future

Structure: If + past simple, would + base verb

• If I had more money, I would travel more.

This describes something imaginary or unlikely right now — not what will happen, but what you imagine.

Third Conditional: unreal past

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

• If I had studied harder, I would have passed the exam.

This talks about the past — something that didn't happen, and its imagined result.

A quick comparison table

Type	Structure	Meaning
Zero	if + present, present	Always true
First	if + present, will + verb	Real future possibility
Second	if + past, would + verb	Unreal present/future
Third	if + past perfect, would have + verb	Unreal past

How to practice

Pick one real situation from your life for each type. For Third Conditional especially, think of a real regret — If I had started English earlier, I would be more fluent now — since real emotional content sticks better than invented textbook examples.