should／ought to＋should／ought to＋have＋过去分词”既可表示本该做而事实上没有做的事,也可以表示惊讶、赞叹等情绪.
如：You should have told her about it the day before yesterday． It’s wonderful that you should have achieved so much in these years．
“情态动词＋have＋过去分词”是很重要的一种句型,除should外,may,might,must,couldn’t,needn’t,ought to等都可以用于这一句型,但要注意使用不同的情态动词句子的意思就有所不同.
ought to与should意思接近,大多数情况下二者可以互换,但是should谈的是自己的主观看法,ought to则更多反映客观情况,在谈到法律、义务和规定时使用.
如：We should／ought to help each other and learn from each other in our work．
She is your mother,so you ought to support her．
We ought to go and see Mary tomorrow,but I don’t think we will．
简单概括：跟 should的用法一样
