I could always tell us apart, even if other people couldn't.

Why in hell couldn't people take care of their garbage?

He'd never learned to tell the difference like some people could.

And of course he could do things that other people couldn't.

The people couldn't camp because the police drove them out using violence.

No doubt some people could, and certainly would have not so long ago.

I wanted to get in on something that most people couldn't, even though all of them knew about it.

What could you have done to protect him, that all those people couldn't?

Most people couldn't; she'd been told that she was hard to get a handle on.

The older people could not, of course, believe that there was no solution to the problem.