Looking on the internet deeply has found these results:

"could have been" is the most popular phrase on the web.

"could had been" 1731,000,000 results on the web	"could have been" 11,780,000,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	"Could have been" being the operative phrase. Looks like you're taking a trip on the good ship "Could have been". The word "evil" was replaced by "red," which means "red" could have been from his unconscious, a freudian slip, so to speak. The rapid take Don't give me "who could it have been?" Don't waste days with "what could have beens" and "what should have beens." up of the new name would seem to bolster the European Commission's belief that one day".eu" could rival".com" and".org" as a leading internet domain name. "It could have been me."

"could had been"

1731,000,000 results on the web

"could have been"

11,780,000,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

"Could have been" being the operative phrase.
Looks like you're taking a trip on the good ship "Could have been".
The word "evil" was replaced by "red," which means "red" could have been from his unconscious, a freudian slip, so to speak.
The rapid take
Don't give me "who could it have been?"
Don't waste days with "what could have beens" and "what should have beens."
up of the new name would seem to bolster the European Commission's belief that one day".eu" could rival".com" and".org" as a leading internet domain name.
"It could have been me."