否定疑问句有否定的一般疑问句和带助动词have, did, would等的特殊疑问句两种形式，用来表达建议、劝说、质问等
例：Wouldn't it be better to go tomorrow?
Why don't we go out for a meal?
正式书写中，或者想对否定做强调的时候（比如表示愤怒、惊讶、或者强烈的建议），可以在否定疑问句的主语后面加not，这种情况下否定一般疑问句比特殊疑问句更常见
例：Did she not realise that she'd broken it? （比Didn't she realise that...?语气弱）
Can you not get there a bit earlier? （比Can't you ...?语气弱）
除了n't表达否定，还可以用never, no, nobody, nothing, nowhere等否定词
例：语气强：Why do you never help?
语气弱：Why don't you ever help?
语气强：Have you nowhere to go? （或者Do you have nowhere to go?）
语气弱：Haven't you got anywhere to go? （或Don't you have anywhere...?）
提供建议的时候，可以用Why not + 动原或者Why don't/doesn't...（但是不可以用Why do not/does not...）:
例：Why not decorate the house yourself? （或者Why don't you decorate...?）
Why didn't....不是用来表示建议的，而是质问对方。
例：Why didn't you tell me that in the first place? （说话人很生气）
否定疑问句句尾降调表示主观意见
例：Haven't you grown!
Doesn't she look lovely!
Didn't it snow a lot!
谢谢啦，不过我已经查到了
否定的一般疑问句及回答