IF Clause Type 4
Form
if + Past Perfect + WOULD HAVE 3 COLUMN
Example: If I had found her address, I would have sent her an invitation.
The main clause can also be at the beginning of the sentence. In this case, don't use a comma.
Example: I would have sent her an invitation if I had found her address.
Note: Main clause and / or if clause might be negative. See Past Perfect andConditional II on how to form negative sentences.
Example: If I hadn’t studied, I wouldn’t have passed my exams.
Use
Conditional Sentences Type III refer to situations in the past. An action could have happened in the past if a certain condition had been fulfilled. Things were different then, however. We just imagine, what would have happened if the situation had been fulfilled.
Example: If I had found her address, I would have sent her an invitation.
Sometime in the past, I wanted to send an invitation to a friend. I didn't find her address, however. So in the end I didn't send her an invitation.
Example: If John had had the money, he would have bought a Ferrari.
I knew John very well and I know that he never had much money, but he loved Ferraris. He would have loved to own a Ferrari, but he never had the money to buy one.