what's this/that/it? It's a book.

[xiaoen]

1. What's it?
It's a book.

2. What's this?
It's a book.

3. What's that?
It's a book.

Hi,
Can I use "it's" when questions are asked by "that", "this" and "it"?

 

[Raymott]

Yes, you can.
But your first question is wrong. You can't say "What's it?" You must say, "What is it?" (Don't ask me why; we just never say "What's it?")

PS: Also the sentence stress is different. "What's this?"; "What's that?"; "What is it?"

 

[Tdol]

You could also use just A book for all three questions.