Refers to: who, who, whose.
Meaning: What?
It can refer to both people and things: which one?
2. The interrogative pronoun in the sentence should be placed before the predicate verb, and the sex and number have not changed, and the case has not changed except who. What, which and who can also be used as determiners. Try to compare:
Question pronoun: Whose books are these on the desk? Whose book is the desk?
What is the direction of American territorial expansion? In which direction is the territorial expansion of the United States?
Qualifier: Whose books are these on the desk? Whose book is the desk?
What event caused most of the east of the Mississippi River to become a part of the United States? What event made most of the land east of the Mississippi River belong to the United States?
Whether you are an interrogative pronoun or a determiner, which and what refer to different scopes. What is an infinite range, and which is a certain range, such as:
Which girls do you like best?
Which girls do you like?
What girl do you like best?
What kind of girl do you like?
4.who is usually the subject and predicative, and who is the object, for example:
Who will chair the meeting? Who will be the chairman?
Who's talking? Who's calling?
Who did you meet in the street?
Who did you meet in the street? (as a verb object)
Who are you taking this book to?
Who are you taking this book to? (As a prepositional object, put it at the beginning of a sentence)
Who did you talk to on campus?
Who are you talking to on campus? As the object of preposition, after the preposition is placed, it cannot be replaced by who. )
5.Whose, what and which can be used as interrogative pronouns:
(1) Subject:
What happened next? What happened afterwards?
Whose is better? Whose is better?
Which one is yours? Which one is yours?
2) Forecast:
What does your father do? What does your father do?
Whose is it? Whose is this?
They are so alike that you can't tell which is which. They are so alike that you can't tell who is who.
(3) Object:
What do you mean? What do you mean?
Which one do you like? Which one do you like?
Who are you going to borrow it from? Who are you going to borrow it from?
(4) attributes:
Which train will you take? Which train do you take?
When shall we meet again? When shall we meet again?
Whose umbrella is this? Whose umbrella is this?
6. Interrogative pronouns can also guide noun clauses, such as:
I don't understand what he is implying.
I don't know what his intentions are.
Can you tell me whose blue shirt is on the bed?
Can you tell me whose blue shirt is on the bed?
I agree with most of what you said, but I can't agree with you completely.
I agree with most of what you said, but I don't entirely agree.