Must have been

Must have been
 

Hi again, another question tonight. I seem to be having trouble wrapping my mind around statements using the English "must have been" construction.

"Those rooms must have been very dirty."
"Esos cuartos deben de haber estado muy sucios."

Am I even close?

Thanks a lot for your time, it's much appreciated.

Learn this construction and you'll be fine:

El cuarto debió estar muy sucio porque cuando salió estaba lleno de polvo.
The room must have been really dirty because when she came out she was covered with dust.

So...

must have been = deber (in preterit) + estar (infinitive)

I must have been crazy ... = debí estar loco ...

I love this forum.

Yes, you are right, you must the word have been for example, David beat me before, but I want opine, you can use these examples:

I must have been sleep for long time.

I must have been stayed long time for my video game.

I can give you alots examples, but well I wanted gave you an hints.