And yet there's one person quite near at hand who in all probability knows where he is, or at all events where he is likely to be. 
There is a person nearby, who is aware of his probable location.
Nobody has the slightest idea, where he is.
A man cutting down a tree.
An individual is having a great time.
The national research council ignored the issue.
The young child is playing doctor.
I enjoy seeing a person lying down, bedridden.
The man is wearing shorts  and carrying a cane.