ought not to do
含有ought to 的反意疑问句,陈述部分是肯定的,疑问部分用shouldn't / oughtn't +主语.在英式英语中用ought to 形式,在美式英语中用should形式.例如：
You ought to see the new picture,shouldn't you?
Teachers ought to be honoured,oughtn't they?
He ought to know what to do,oughtn't he?/ shouldn't he?
ought to 是情态动词 与can may must 一样