Using the Third Conditional in English

The third conditional in English is used to talk about hypothetical situations or events in the past. It is used to express a situation that did not happen in the past, and therefore, it cannot be changed. The third conditional follows this structure:

If + past perfect (had + past participle), ...would have + past participle.

Here are some examples of the third conditional in action:

1. If I had studied harder, I would have passed the exam. (But I didn't study hard, so I didn't pass.)
2. If she had called me, I would have gone to the party. (But she didn't call me, so I didn't go.)
3. If they had left earlier, they wouldn't have missed the train. (But they didn't leave earlier, so they missed the train.)

In each of these examples, the "if" clause describes a situation or action in the past that did not happen. The "would have" clause describes the hypothetical result or consequence of that situation.

The third conditional is often used to express regret, criticism, or disappointment about past events, or to speculate about what could have happened differently if circumstances had been different.