A typical 3rd conditional uses this
formula: If + subject + past
perfect (had + past participle
verb), subject + would have +
The first half (If + subject + past
perfect) is known as the
'conditional clause' or 'if clause'.
The second half (subject + would
have + past participle verb) is
known as the 'main clause'.
These can be placed in either
order with no change in meaning.
When the main clause comes first,
we do not use a comma between
If I had known you were coming, I
would have baked a cake.
I would have baked a cake if I'd
known you were coming.
The third conditional is used to
wonder and imagine about past
events that did not happen.
If I'd been born in Spain, I would
have learned Spanish, not English!
What would you have done if
you'd failed your test?
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