On another language forum, I was told that sentences like,
This is John's friend who I hate.
This is my car which I've had for two years.
etc. are wrong and we should say these instead:
This is the friend of John who I hate.
This is the car of mine which I've had for two years.
Do you agree with this? Can't the structure in the first pair of examples I gave be used by native English speakers. At least using a pause maybe, like as "This is John's friend, who I hate"? Maybe even without a pause/comma? They don't seem unnatural to me. I would like to receive your knowledge and thought on this.
Context of the sentences: In the first sentence, I am showing someone the picture of somebody I dislike. In the second one, I am showing someone a car in my garage.