Answer:
I'm sure
Adnan: is this your book?
Noman: yes, this is my book
Adnan: are you sure?
Noman: yes, I am sure.
Adnan: is your book red?
Noman: yes my book is red
Adnan: there you go, have a look is this your book?
Noman: I'm sorry. This isn't my book
