【归纳】 ★could have done可以表示“过去本来能够做某事而实际上没有做”。如: I could have come here a little earlier, but I''m late because of the bad traffic. ★must have done表示对过去已经发生过的情况的肯定推测,语气较强。如: She must have received the book; I sent it a month ago. ★may / might have done表示对已经发生过的情况的肯定推测,语气稍弱。might have done还可表示“本可能做某事而实际上没有做”。如: She didn''t come on time. She may / might have missed the bus. He might have given you more help, but he was very busy then. ★should / ought to have done表示“本该做某事而实际上没有做”,其否定形式表示“本不该做某事而实际上做了”,通常含有责备的意思。如: The flowers have died. I should / ought to have watered them often. You shouldn''t / ought not to have told them the truth. ★needn''t have done表示“本不必做某事而实际上做了”。如: It is warm today. You needn''t have worn your coat. 注意:didn''t need to do与needn''t have done都表示“过去不必做某事”,但didn''t need to do通常表示“没必要做,实际上也没做某事”,而needn''t have done则表示“虽然没必要做,但已经做了某事”。如: He didn''t need to get up early on Sunday, so he stayed in bed until 10 am. It''s only five minutes''walk. We needn''t have taken a taxi. 【即学即练】用“情态动词+ have done”结构完成下列句子。 1. You ________ (wash) the wound with cold water, but you used hot water. 2. I am not feeling well in the stomach. I ________ (eat) so much just now. 3. There was enough time. You ________ (hurry). 4. I ________ (lend) you the money. Why didn''t you ask me? 5. They ________ (go) out because the light''s out. 答案【即学即练】 1. should / ought to have washed 2. shouldn''t / ought not to have eaten 3. needn''t have hurried 4. could / might have lent 5. must have gone |
|