There are a number of words in the English language that are used primarily to make questions; these words are ‘question words’, sometimes known as ‘WH question words’, owing to the fact that all of them start with the letter ‘w’, except one which starts with ‘h’. Here are the question words and their functions:
‘What’ is used when asking for information about something, as in:
What did you do last evening?
What would you like for dinner?
What did you say when you were caught?
‘When’ is used when asking for time, as in:
When do you arrive?
When is the show?
When did that happen?
‘Where’ is used when asking for place, as in:
Where do we go now?
Where have you kept the book?
Where do you go for your tuitions?
‘Who’ is used when asking for identity of person or persons, as in:
Who is that?
Who wroteMoby Dick?
Who called earlier?
Note: For the differences between ‘who’ and ‘whom’ (a variation of the former), see the article Who and Whom
‘Whose’ is used when asking about possession, as in:
Whose car is this?
Whose place are you staying at?
Whose are these shoes?
‘Which’ is used to ask about choice, as in:
Which flavour of ice cream would you like?
Which route do you think we should take?
Which of the two is better?
‘Why’ is used when asking for reasons, as in:
Why would you say something like that?
Why does the food smell bad?
Why did you not go for work today?
‘How’ is used when asking about manner or quality or condition, as in:
How did you do that?
How was the movie?
How is life?