In class today, I was working on perfect modals.
So not to bore you, that means phrases like "could have been" or "should have played" etc and so on.
This was my first time going to a class that had been meeting for a few weeks. I had to miss the first few weeks because of a conflict at another school.
Anyway, I'm a pretty friendly guy, and a couple of the students in this class I have had previously, so I am sure they told the other students "This guy is nice/friendly/funny" etc.
So the students are guessing where I could have been because I was gone. They then followed this up with what I should have been doing.
Mark could have been gambling in Las Vegas. He should have been teaching English.
One of the last groups says:
Mark could have been drinking alcohol. He should have been losing weight.