Grammar - past perfect...?

I used to have teachers that told me using "have been" is not the best way to go... for example the following sentence...

"Did you know that 80% of all VET visits are checkups and could have been done by a nurse's assistant?"

b/c of "are" I feel that no matter what this should read "could be"... but lets say "Are" was replaced with "were"...

... any thoughts will be helpful. Thanks

here's another one...

... before finally being seen by a doctor...

isn't there something awkward about "being seen"

any suggestions?

OK first of all "have been" is the Present Perfect (and have been doing is the Present Perfect Continuous). "Had been" is the Past Perfect (had been doing is the Past Perfect Continuous).

Usually when teachers disapprove of "have been" it's because it can be part of the passive, as it is here "have been done by a nurse's assistant" as opposed to "a nurse's assistant could have done them". The subject of the sentence isn't the one doing the action. Same goes for your "being seen" example. "Before the doctor finally sees them..."

The tense is a bit questionable, depending whether there's still the chance to change the circumstances and have the nurse's assistant do them. If so, you would probably be better off with "could be done" or even "can be done". If not, as when you use "were", you need "sould have been done".

I don't much like the word "done" here either. Usually you'd "make" a visit (or is that not what the nurse's assistant could have done?).


Edited to add: "Did" is not the Past Perfect, it's the Simple Past. The Past Perfect is used for an action in the past that was completed before another action in the past. (for example: I had mentioned the Past Perfect before the other answerer said no one had referred to it).

In your example, you are using "have been," which is Present Perfect Continuous. The Past Perfect Continuous is "had been." Since you use "are" then I would say your word choice is correct. If you were talking about a statistic from a previous year, then you would want to use "had been."

For example:

"Did you know that last year 80% of all Vet visits were checkups and could had been done by a nurse's assistant?"

By saying it the way you are, you are indicating something that is still happening ... in the present. I personally would write it the way you have written it. But, I am not an English teacher, so what do I know?

It is interesting that you cited "Past Perfect" in your main question, but neither you nor the answers given as I write this mention it again.
Past perfect is an action completed in the past. The word "Did" is the only example of this.
The whole problem could be solved by asking "Do you know that ....check-ups that could be done (I prefer "made")... .
Why ask what used to be known?
"Beeing seen" is fine; but why "finally"?