Or.....................

In "Which car is yours?", which is an interrogative adjective.

In "Which is yours?", which is an interrogative pronoun.


Stick with that.

This forum is starting to have too many cooks.

Sorry GM, but I wouldn't go along with you on that either.

In traditional grammar, determinatives form a subclass of adjectives. Thus the "which" in "Which car is yours"? was treated as a kind of adjective based on some vague idea that it 'modified' the noun "car" (which it doesn't). But in modern grammar, determinatives are treated as a distinct primary group, so this "which" is a determinative, not an adjective.

In the case of "Which is yours"?, things are a tad complicated. The crucial thing about "which" is that it differs from all the other interrogative words in having a property called 'selective', implying that the answer to the question is to be selected from some definite set; in this case the set is "some cars". Function-wise, this "which" is called a 'fused determiner-head', so in a tree diagram, "which" would carry the function label 'Determiner-Head' and the category label 'Deteminative'.



PaulM