'Which', 'whose' or something else?
First of all, I'm not a native speaker so I can't rely on my intuition in this specific case.
For a very long time I was sure that "whose" was the widely used possessive form of both "who" and "what". But at one point someone told me that the correct possessive of "what" is actually "which". This sounded extremely awkward, like "the car which door got scratched", and yet over the years I actually encountered sentences like this two or three times.
So, could someone clear this up please? Is "whose" the only correct possessive of "what", or is "which" also correct? In which case, has "which" become obsolete or does it still feel acceptable to native speakers?
Examples of the use of "which" like this: