The Third Conditional – Form and Use

The third conditional is used to talk about imaginary situations in the past, situations that didn’t happen and their imaginary results.

To form the third conditional we use the past perfect in the “if” clause and “would have” with the past participle in the result clause.

[Condition] + [Result]
[If + past perfect] + [would have + past participle]

If they hadn’t offered me a job, I wouldn’t have left my previous company.
If you hadn’t graduated from college, you wouldn’t have gotten the job.

[Result] + [Condition]
[Would have + past participle] + [if + past perfect]

They would have offered me a job if I had had more experience.
We wouldn’t have finished the project on time if Jim hadn’t helped us.