In English there are seven ‘Wh…’ questions. Here’s what they are and how they are used:

What is used for a thing.

‘What is it?’

Who is used for a person. Whose has the same meaning but it is always followed by a noun.

Who were you talking to?’

‘Whose car is that?’

Why is used for a reason.

‘Why were you late?’

When is used for a time or date

‘When did you start working here?’

Which is used for a choice.

‘Which do you prefer, tea or coffee?’

Where is used for a place.

‘Where do you live?’

How is used for an amount or the way.

‘How much does it cost?’

‘How do I get to the station?’

Forming wh-questions

With an auxiliary verbWe usually form wh-questions with wh- + an auxiliary verb (be, do or have) + subject + main verb or with wh- + a modal verb + subject + main verb:

Be: When are you leaving?

Do: Where do they live? Why didn’t you call me?

Have: What has she done now? What have they decided?

Modal: Who would she stay with? Where should I park?

Negative wh-questionsWhen we ask negative wh-questions, we use the auxiliary verb do when there is no other auxiliary or modal verb, even when the wh-word is the subject of the clause:

Affirmative with no auxiliary Negative with auxiliary doWho wants an ice cream? Who doesn’t want an ice cream?Which door opened? Which door didn’t open?

Prepositions and particles with wh-questionsWe can use wh-words and phrases after prepositions in more formal questions:

Where will the money come from?From where will the money come? (formal)

In informal styles, especially in speaking, the preposition may be separated and placed at the end of the question clause:

What will I talk to her about?Who should we send the invitation to? (informal)Whom should we send the invitation to? (formal)To whom should we send the invitation? (more formal)For what reason did she leave him? (formal: preposition + wh-phrase)