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
She would have ordered the TV online if the shipping cost had been lower.
They wouldn't have tried to sell the product that way if they'd done their market research.
If they had known about the project before, this project wouldn't be listed on short notice.
If we had known the balance of payments, we would have recommended an alternative payment plan.
Do not use a comma, when placing the result clause first.
She would have ordered the TV online if the shipping cost had been lower.
The capital allowance would have been granted if the merger had been approved by regulators.