vs
QUICK ANSWER
"If I could" is a phrase which is often translated as "si pudiera", and "I would have" is a phrase which is often translated as "hubiera". Learn more about the difference between "if I could" and "I would have" below.
if I could()
A phrase is a group of words commonly used together (e.g., once upon a time).
1. (general)
I would have()
A phrase is a group of words commonly used together (e.g., once upon a time).