I was studying today's newspaper and this appeared:
How did the metals get there?
Metals are used in practically every product we use. Even detergents and shampoos have traces of them. Nanoparticles are used to limit body odour in socks, for instance. A lot of this is absorbed by the body and discarded as waste, which enters the sewage system and treatment plants.So I could have been a millionaire by now?
Since the idea isn’t to sift through individual toilet refuse, no, you would still probably be where you are now. To actually mine the sewage, wastewater is treated through physical, biological, and chemical processes, resulting in treated water and biosolids. The biosolids, says US researchers, may be as good as a gold mine.
Is the usage of could have been correct? If yes, then how does it differ from I could be a millionaire by now?
Please explain this to me.
Best Answer
First of all, the difference between "could have been" and "could be" is that both of them indicate that it's impossible to get the result but why it's impossible is the difference, in could have been, it's impossible because it's past. It could have been possible if he did it in the past.
But with 'could be' it's impossible because it's unreal situation, it could have never happened in the past or now.. It's a hypothesis or imagination.
So here in your context the use of 'could have been' mean that it might have been possible that he becomes a millionaire if he started collecting that waste in the past.. It's real, not imaginary but it's impossible because it wasn't done in the past.