语法学习技巧|情态动词+ have +过去分词

1) may have + done sth, can have + done sth表示过去，推断过去时间里可能发生的事情。
Philip may have been hurt seriously in the car accident1.
Philip can have been hurt seriously in the car accident.
2)must have +done sth，对过去时间里可能发生的事情的推断，语气较强，具备一定，谅必的意思。
---Linda has gone to work, but her bicycle is still here.
---She must have gone by bus.
3) ought2 to have done sth, should have done sth
本应该做某事，而事实上并没做。否定句表示不该做某事而做了。
You ought to have been more careful in this experiment3.
He ought not to have thrown the old clothes away.（事实上已扔了。）
ought to 在语气上比should 要强。
4) needn't have done sth 本不必做某事
I dressed very warmly for the trip, but Ineedn't have done so. The weather was4 hot.
5) would5 like to have done sth 本计划做某事
I would like to have read the article6, but I was very busy then.