What Would Have Happened
Third Conditional
The third, or 'past', conditional is used to imagine past outcomes different than what actually took place. This conditional is used to express what would have been different if a person had done something differently.
'If' clause - past perfect + , + result clause - would + have + verb (conditional perfect tense)
Examples of Past Unreal Outcomes
He would be locked away in prison if human rights laws had been universally enforced.
She wouldn't have taken the brochure if she'd known it had a tracking device stapled to it.
We would have lost our honest broker status if the newspaper had run the story.
She would have started a business-friendly international NGO if Susan had retired.
Do not use a comma, when placing the result clause first.
She would have started a business-friendly international NGO if Susan had retired.
They would have rewritten the bylaws if he had won his case against them.