Sometimes we answer a statement by asking for more information. Questions of this kind have a very simple structure.
Study the following examples.

‘Susie is quitting her job.’ ‘Why?’ (More natural than ‘Why is Susie quitting her job?’)

‘I’m not coming to the party.’ ‘Why?’ (More natural than ‘Why are you not coming to the party?’)

‘Alice is getting married.’ ‘When?’(More natural than ‘When is Alice getting married?’)

‘The principal wants to see you.’ ‘What for?’(More natural than ‘For what does the principal want to see me?’)

‘The trains aren’t running?’ ‘Why not?’(More natural than ‘Why aren’t the trains running?’)

Negative statements

We can convert a negative statement into a question in two different ways.

Compare the example given below.

Ramya does not like to watch TV.

We can convert this into a question in two different ways.

Does Ramya not like to watch TV? (This is somewhat formal.)

Doesn’t Ramya like to watch TV? (This is less formal.)

She didn’t get the first prize.

Didn’t she get the first prize? (informal)

Did she not get the first prize? (formal)

Sophia called in the morning.

Did Sophia not call in the morning? (formal)

Didn’t Sophia call in the morning? (informal)

John did not pass the test.

Didn’t John pass the test? (informal)

Did John not pass the test? (formal)