Who is your dad by profession?
Those who knows english language, they can read english books.
Why did you come early?
Who are you meeting today?
When are you going for work?
Those who likes to read books, they take it from the library.
Whose letter is this? - it's ours.
Who is this person? - this person is our teacher.
What kind of books are these? - these are good books.
Which one of these books is ours? - all of them are yours.