I have a question about relative clauses and possession, the answer to which I can find nowhere and I was hoping you could help me with that. We can say:
- This is the book whose title I had forgotten.
- This is the book the title of which I had forgotten.
- This is the book that I had forgotten the title of.
In sentence 3 above, we can say that "the title" is the object in the relative clause, which makes the last structure with "that...of" sound great.
What about the case when it is the subject of the relative clause? Eg.
- This is the book whose title is very clever.
- This is the book the title of which is very clever.
Is there a third case with "that...of"? And if so, is it like one of the following cases?
- This is the book that the title of is clever.
- This is the book that is clever the title of.
In my opinion, the former structure sounds a lot better, but still I'm not sure if it is correct. I'd appreciate any help!