A question is that form of a sentence which seeks confirmation or some information with regard to time, place, manner, reason, etc.
e.g. Do you have brothers and sisters? [Seeking confirmation: Yes or No]
When will the taxi arrive? [seeking information about time]
Where have you put my key? [seeking information about place]
How does she dance? [seeking information about manner]
Why is Ajith absent today? [seeking information about reason]
Some common words used to seek information are
What, when, where, why, how, whose, which, how much/many.
The interrogative pronouns who, what, whom, whose, which and the interrogative adverbs where, when, why and how are used to frame information questions.
The structure ‘how + an adjective/adverb’ may also be used to frame information questions