表示过去未实现的希望或计划的句型分为：

1 动词expect, intend, hope, mean, plan, promise, suppose, think, want, wish等的过去完成时态，或者用一般过去时态后面接不定式的完成形式表示过去未曾实现的愿望，常意为"本来希望、计划、打算……做……但实际没做到"。

I had planned to go abroad after graduation, but my mother was ill。

我本来计划毕业后出国的，但是我母亲生病了。

2 情态动词should, could, might, ought to等后接完成时，表示过去本该做、打算做、想做而未做的事情。结构如下：

should have done=ought to have done本应该做而没做

could have done 本可以做某事而没做

might have done 本可以做而没做

They ought to have apologized.

他们本该道歉的。

I missed the important meeting. You should have reminded me of attending the meeting yesterday.

我错过了这次重要会议。你昨天本该提醒我参加这次会议的。