First and Second Conditional Explained

Conditional sentences describe what happens if something else happens. The first and second conditionals differ in how likely the situation is.

First conditional: real and possible

Use it for situations that may well happen in the future.

If + present simple, will + base verb

• If it rains, we will stay at home.
• If you study, you will pass the exam.
• She will be angry if you forget.

Never put "will" in the if-clause: "If it will rain" is wrong.

Second conditional: unreal or unlikely

Use it for imaginary, unlikely or impossible situations in the present or future.

If + past simple, would + base verb

• If I won the lottery, I would buy a house.
• If she had more time, she would learn Spanish.
• I would help you if I knew how.

The past tense here does not mean past time. It signals that the situation is not real.

"Were" for all persons

In the second conditional, were is often used with I, he, she and it, especially in formal English: "If I were you, I would apologise." This is the standard way to give advice.

Real or unreal?

Sentence	Meaning
If I have time, I will call you.	It is possible; I may have time.
If I had time, I would call you.	I probably do not have time.

Beyond the basics

The third conditional goes one step further and talks about the unchangeable past: "If I had left earlier, I would have caught the train." It uses if + past perfect, would have + past participle.

Common mistakes

• Wrong: "If I will see him, I will tell him." Right: "If I see him, I will tell him."
• Wrong: "If I would have money, I would travel." Right: "If I had money, I would travel."

Practice

• First vs Second Conditional quiz — Real possibility or imaginary situation?
• Third Conditional quiz — What would have happened if the past had been different?