文档介绍：***高考高中起点英语语法精选
***高考高中起点英语语法精选
***高考高中起点英语语法精选
成考高起点英语语法归纳练****br/>（一）情态动词
一、情态动词的现在完成式的用法
情态动词现在完成式主要有两个功能：表示已经发生的情况和表示虚拟语气。在这两个
方面 must/mustn't，； can/cann't； need/needn't； may/mayn't ；might/mightn't ； should/shouldn't ；
ougtht 等情态动词＋完成式表示的意思是有一定区别的
。
1）must have+过去分词，表示对已发生情况的肯定推测，译为 “（昨天）一定 ”。如：
My pain __________ apparent the moment I walked into the room ， for the first man I met
asked sympathetically ： “ Are you feeling all right？ ”
[A] must be [B] had been [C] must have been [D] had to be
（答案为 C）
2） can't / couldn't have+过去分词，表示对已发生情况的否定推测，译为 “（昨天）一定
没 ”。如：
Mary __________ my letter ； otherwise she would have replied before now.
[A] couldn't have received [B] ought to have received
[C] has received [D] shouldn't have received
（答案为
A ）
***高考高中起点英语语法精选
***高考高中起点英语语法精选
***高考高中起点英语语法精选
3） may / might have + 过去分词，表示对已发生的事情做不肯定、可能性很小的推测，或事实上根本没发生，译为 “也许 ”。如：
At Florida Power's Crystal River plant ， a potentially serious leakage of radioactive water may
have been unknowingly caused by an electrician.
。
1） needn't have + 过去分词，表示做了不必做的事，相当于 “ didn't need to do，译为”“其
实没必要 ”。如：
You needn't have come over yourself.
As it turned out to be a small house party ， we __________ so formally.
[A] needn't dress up [B]did not need have dressed up
[C] did not need dress up [D] needn't have dressed up
（没有必要穿的那么正式，体现是说话者的建议，实际结果是否真的穿的很正式没有确定，答案为 D ）
2）should have + 过去分词， 表示应该做某事但实际上未做， 译为 “本应该 ” should not +
have 过去分词表示本不应该做某事但实际上做了，译为 “本不应该 ”。如：
I regret having left the work unfinished ； I should have planned everything ahead carefully.
我本来应该事先认真地把每件事情规划的很好，但实际上作者还是没有规划好，以至工作没有完成。
3） ought to have +过去分词，表示动作按理该发生了，但实际上未发生，译为 “该 ”，
与 should 的完成式含义类似。如：
he porter ought to have called the fire-brigade as soon as he saw the fire in the stock ， which went up in smoke .
***高考高中起点英语语法精选
***高考高中起点英语语法精选
***高考高中起点英语语法