This construction bothers my wife, so I decided to investigate.

The problem with people using “If he would have” where they mean “If he had” instead is that the two expressions have different meanings.

• The expression “If he would have” assumes that he would not.
• The expression “If he had” assumes only that he did not.

Look at these two constructions:

1. If John would have gone to the golf course at 8 a.m., then we would not have had to call Jim.
2. If John had gone to the golf course at 8 a.m., then we could have started on time.

Here are the explanations for the above two constructions:

1. John would not go to the golf course, so we had to call Jim.
2. John did not go to the golf course, so we did not start on time.