Third Conditional

Unreal past results: If + past perfect, would have + V3

advanced

When to Use

•Imagining different past results: If I had studied, I would have passed.
•Expressing regret: If we had left earlier, we wouldn't have missed it.
•Criticism: If you had told me, I could have helped.
•Hypothetical alternatives to past events.
•Combining with mixed conditionals (past condition → present result).

How to Form

Affirmative (+)

If + past perfect, would have + past participle

Negative (-)

If + past perfect, wouldn't have + past participle

Question (?)

What would have happened if + past perfect?

💡 Could have/ might have also possible; keep past perfect in if-clause.

Examples

✓If you had called, I would have come.

✗If you called, I would have come.

Use past perfect in if-clause.

✓If they had known, they wouldn't have gone.

✗If they knew, they wouldn't have gone.

Third conditional needs had + V3.

✓What would you have done if you had lost your phone?

✗What would you do if you had lost your phone?

Use would have + V3 for past result.

Common Mistakes

💡 Practice Tips

• Pattern: If + had + V3, would have + V3.
• Use could have/might have for possibility/ability in results.
• Avoid would in the if-clause.
• Contrast with second conditional (unreal present/future).

second-conditional mixed-conditionals past-perfect 📝 conditionals-advanced 📝 third-conditional-quiz

Third Conditional

Unreal past results: If + past perfect, would have + V3

advanced

When to Use

•Imagining different past results: If I had studied, I would have passed.
•Expressing regret: If we had left earlier, we wouldn't have missed it.
•Criticism: If you had told me, I could have helped.
•Hypothetical alternatives to past events.
•Combining with mixed conditionals (past condition → present result).

How to Form

Affirmative (+)

If + past perfect, would have + past participle

Negative (-)

If + past perfect, wouldn't have + past participle

Question (?)

What would have happened if + past perfect?

💡 Could have/ might have also possible; keep past perfect in if-clause.

Examples

✓If you had called, I would have come.

✗If you called, I would have come.

Use past perfect in if-clause.

✓If they had known, they wouldn't have gone.

✗If they knew, they wouldn't have gone.

Third conditional needs had + V3.

✓What would you have done if you had lost your phone?

✗What would you do if you had lost your phone?

Use would have + V3 for past result.

Common Mistakes

💡 Practice Tips

• Pattern: If + had + V3, would have + V3.
• Use could have/might have for possibility/ability in results.
• Avoid would in the if-clause.
• Contrast with second conditional (unreal present/future).

second-conditional mixed-conditionals past-perfect 📝 conditionals-advanced 📝 third-conditional-quiz

Third Conditional

When to Use

How to Form

Examples

Common Mistakes

💡 Practice Tips

Related

Third Conditional

When to Use

How to Form

Examples

Common Mistakes

💡 Practice Tips

Related

When to Use

How to Form

Examples

Common Mistakes

✗If I had know, I'd help.

✗If he had studied, he will have passed.

✗If you would have told me, I would have come.

💡 Practice Tips

Related

When to Use

How to Form

Examples

Common Mistakes

✗If I had know, I'd help.

✗If he had studied, he will have passed.

✗If you would have told me, I would have come.

💡 Practice Tips

Related