As you see in this question of mine I have focused on objects and animals.
[color=green]1. Animals of the world. = correct
[color=red]2. Animals of the world’s. = incorrect
[color=green]3. The tire of the car. = correct
[color=red]4. The tire of the car’s. = incorrect
This is my question: Why “He is a friend of Alex’s” is correct but " [color=red]… of the world’s" and “[color=red] … of the car’s” is not?
The structures are same {Alex’s} - {World’s} - {car’s}
To me, there is no difference between the two.
As an aside, as far as I’m concerned, “a friend of Alex” is just fine and the idiomatic double genitive in “a friend of Alex’s” is a bit of overkill, BUT some say there is a nuance between the two usages:
a friend of Alex – one who befriends Alex; one who looks upon Alex as a friend
a friend of Alex’s – one whom Alex befriends; Alex looks upon the other person as a friend
Again, no real difference there for me, though I suppose one could argue that
He is a friend of mine. – He is one of my friends.
He is my friend. – No additional information there; he might just as well be my only friend.
All right, I think. Same comments as to (1) and (2).
Same comments as for (1) and (2).
I’d probably say:
A friend of Mohan('s) is preparing (himself) for admission into college.
A friend of Mohan('s) is preparing (himself) for college admission exams.
(You would use the definite article if you mean a specific college.)
But I think they are all right as they stand.
I probably didn’t express that in the best way possible, BUT you should be able to see how your new examples are different from the ones in your original post.
What I was saying was that in order for the double genitive to be legitimate, the object of the preposition “of” has to be animate. In other words, the “possessor” cannot be an inanimate object (i.e. a non-living thing).
car - inanimate object
Alex - a person’s name; human; animate object, obviously!