what
asking for information about something
What is your name?
asking for repetition or confirmation
What? I can't hear you.
You did what?
when
asking about time
When did he leave?
where
asking in or at what place or position
Where do they live?
which
asking about choice
Which colour do you want?
who
asking what or which person or people (subject)
Who opened the door?
why
asking for reason, asking what...for
Why do you say that?
why don't
making a suggestion
Why don't I help you?
how
asking about manner
How does this work?
asking about condition or quality
How was your exam?
how much
quantity (uncountable)
How much money do you have?