Question words are:
What: asking for information about something.
"What is your name?"
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.
"Who opened the door?"
How: asking about condition or quality.
"How was your exam?"
