Third conditional

Use the third conditional to imagine a different result for a past situation that cannot now be changed.

When do we use it?

Combine if plus past perfect with would have plus a past participle.

Form

Use if + had + past participle, would have + past participle.

• If I had known, I would have called.
• She would have passed if she had studied.

Key contrast

At B2, choose the form from the complete context: sequence, viewpoint, degree of certainty and clause structure all matter.

Common mistakes

• If I would have known. → If I had known.
• I would have call. → I would have called.

Remember

Use the third conditional to imagine a different result for a past situation that cannot now be changed.

Quick check

• Identify the time relationship or intended meaning.
• Check the auxiliary, participle and clause pattern.
• Eliminate answers that fit the words but not the context.