WHEN WE ADD か TO A QUESTION WORD, WE CHANGE THE MEANING OF THE WORD. e.g. WHAT BECOMES SOMETHING, WHO BECOMES SOMEBODY, WHERE BECOMES SOMEWHERE.
- These sentences are always in the positive.
HERE'S ANOTHER WAY TO LOOK AT IT:
なに - なにか
- what - something
だれ - だれか
- who - somebody
いつ - いつか
- when - sometime/someday
どこ - どこか
- where - somewhere
どちら - どちらか
- which (of two) - either one (out of the two)
どれ - どれか
- which - any one (out of three or more)