This structure is used to suggest something for other people’s consideration and acceptance. It is a more direct way of making a suggestion.
- Why not buy now and pay later?
- Why not suspend that guy?
- Why not punish that boy?
- Why not hire a more competent person?
- Why not ask him?
- Why not consult a specialist?
- Why not throw a party in his honour?
- Why not buy a new car?
- Why not change jobs?
- Why not file a police complaint against him?
Note that in this structure we cannot use a pronoun after why not?
- Why not get that car serviced? (NOT Why not we get that car serviced?)
The same idea can be expressed using the structure ‘why don’t we?’
- Why don’t you suspend that guy?
- Why don’t you hire a more competent person?
- Why don’t you ask him?
- Why don’t you consult a specialist?
- Why don’t you buy a new car?
- Why don’t you find another job?
- Why don’t you start dieting?
- Why don’t we make another attempt?
- Why don’t we ask him?
Why in replies
In short replies to negative statements, we usually use ‘Why not?’ In replies to affirmative statements, we usually use ‘Why?’
- ‘She has decided to call off her wedding to Peter.’ ‘Why?’
- ‘She isn’t coming with us?’ ‘Why not?’
- ‘We can’t depend on him.’ ‘Why not?’
The structure ‘Why should’ can be used to suggest surprise or anger.
- I don’t understand why she should hate me.
- I don’t see why I should pay for your drinks.