I read something that got me confused regarding the usage of "who" and will need your help to make things much clearer to me. It says that a comma before "who" will dictate which noun in the prepositional phrase the "who" is referring to. I'll give you 2 examples:
1) I borrowed the car of John, who is my neighbor
because there is a comma before "who", "who" is referring to the subject of the prepositional phrase "car."
2) I borrowed the car of John who is my neighbor
because we don't have a comma before "who", then "who" is referring to the object of the prepositional phrase "John."
It also claims that the same thing goes with "which" when there is a prepositional phrase before it. Does "which" always refer to the word immediately before it no matter whether it is the subject or the object of the prepositional phrase? For example, using the same example above:
3) I borrowed the car of John, which is expensive.
I just came up with this example so i'm not sure how wrong or correct this is, but for the sake of creating an example, i made this one up. does this mean that "which" refers to "car" or "john." I just need to end this confusion once and for all.
Where did you read this stuff?