Interrogative Pronouns
who, whom, which, what, whose
They are used to ask questions
WHO ? WHOM and usually WHICH are used to refer to people
WHICH and WHAT are used to refer to things and animals
Example
WHO told you ?
WHOM did you tell ?
WHAT do you want ?
WHICH CAME FIRST ?
There is one car missing. WHOSE hasn't arrived ?
Note
1. We sometimes use the suffix EVER to make compounds from some of these pronouns (mainly WHOEVER, WHATEVER, WHICHEVER)
2. When we add EVER we use it for emphasize , often to show confusion or surprise
Example
WHOEVER would want to do such nasty thing ?
WHATEVER did he say to make her cry like that
They are all fantastic, WHICEVER will you choose ?