It is important to know exactly how to form questions using these words. The rules also apply to other question words like "where", "how" and "who".
* We usually form wh-questions with wh- + an auxiliary verb (to be, to do or to have) + a subject + the main verb .
is used to obtain information or ask the reason for something.
is used to ask about a time or an occasion.
Look at some examples:
* Why do they always drive so fast?
Perché guidano sempre così veloce?
* Why is the sky blue?
Perché il cielo è blu?
* Why is John staying at your house at the moment?
Perché adesso John sta a casa vostra?
* When are they leaving?
Quando vanno via?
* When do you usually go to the supermarket?
Di solito quando vai al supermercato?
* When do the school holidays start?
Quando iniziano le vacanze per le scuole?
* We also use this form with modal verbs (can, should, must, etc):
wh- + a modal verb + a subject + the main verb.
For example,
* Why can't I go to the party, Mum?
Mamma, perché non posso andare alla festa?
* When must we give you back your computer?
Quando ti dobbiamo ridare il computer?
Remember that why and when are not yes or no questions and require a given answer.
For example,
Why are you so tired today?
Perché oggi sei così stanco?
Because I went to bed late last night.
Perché ieri sono andato a dormire tardi.