I have always said,

Das hätte gebaut werden können.

  • That could have been built.

But recently I have heard people say

Das könnte gebaut worden sein.

This has confused me. I assume this means "er hätte das machen können" and can also be written as "er könnte das gemacht haben" according to the above.

Please can someone tell me the difference between both?

  • There is a difference between the two, but I'm struggling to pinpoint it and translate it to English. I'd say 1) is something like "it would have been possible to build that" maybe if more effort had been put into it. 2) indicates (IMHO) uncertainty as to whether it was really built "it might have been built, but we don't really know". – user35915 Oct 28 '16 at 0:40
  • 2
    You could also say "das könnte 1950 gebaut worden sein" if you're trying to put an age on a building for example. If you say "das hätte 1950 gebaut werden können" I would interpret that as you telling me that it would have been possible to build it with 1950 technology. Although I do consider German to be my native language, I don't know any German grammar and can therefore only tell you how I feel about those expressions. – user35915 Oct 28 '16 at 0:45

The first has the meaning of:

If some circumstances were different, then probably the building would have been built. But it wasn't built.

The second means:

I am not sure, when or if this building was built, but at least it would have been possible to build it at that time.

So both are conditional clauses, but refer to different knowledge about the facts.

  • Wrongly using the second construction when intending the first meaning is becoming more common, even among professional writers. I suspect that, as so often, this is due to interference from English, which does use the second form to convey the first meaning. – Kilian Foth Oct 28 '16 at 6:28

The point is that

Das könnte gebaut worden sein

is not past conditional, but rather present conditional (The conditional still exists today. Replace the participle construct that says "has been built" with an adjective like

Das könnte blau sein

and it's obvious it could be blue even today.)

So, your two examples are obviously two different tenses, and thus obviously mean two different things.

Das hätte gebaut werden können

Is definitely past conditional and the conditional no longer exists today. If it's not clear, use the same trick as above to change to

Das hätte blau sein können

And it again becomes obvious the possibility of being blue no longer exists.

Not the answer you're looking for? Browse other questions tagged or ask your own question.