职称英语语法:第十四讲
第十四讲 虚拟语气的句型分类和用法
虚拟语气的句型分类和用法:
虚拟语气可以粗略地分为两大类:
第一类:should 型虚拟式第二类:were 型虚拟式
1.should 型虚拟式:should + 原形动词(往往省去should, 特别是在考试时)
这类虚拟式最多用在以下词或句型中:
(1) It is necessary that…的主语从句中,如:
It is necessary that the chief should be present personally at the meeting.(主任有必要亲自参加这次会议。)
只要看到"necessary",马上要想到这是"should型"虚拟式。
记住下面构成"should型"虚拟式的词:
essential (必要的) / important(重要的) / necessary(必要的) / imperative(迫切的)/ impossible(不可能的)/ natural(自然的)/ preferable(更好的)/ advisable(合理的)/ desirable(理想的)/ urgent(紧迫的)/ incredible(难以想象的)
(2) order (命令) / recommend(推荐)/ suggest(建议)/ demand(要求) / command(命令)/ propose(建议)/ require(要求)/ request(请求) / insist(坚持认为)/ urge(主张) / advise(劝告)/ ask(要求)/ prefer(宁愿)/ desire(愿望)/ move(提议)/ vote(提议)
由这些词构成的宾语从句,主语从句、表语从句、同位语从句或其他有关句型时,都要使用"should型"虚拟式,例如:
It was ordered that the medicines (should) be sent there by plane at once. (主语从句)
The order was that the medicines (should) be sent there by plane at once.(表语从句)
The chief ordered that the medicines (should) be sent there by plane at once.(宾语从句)
The order that the medicines (should) be sent there by plane at once was sent to the branch office.(同位语从句)
(3) 在 in case / lest = for fear that(以免… / 以防…) 结构中,例如:
He took a raincoat with him in case it should rain (或用真实语气:…in case it rained)
She put a wool blanket over the child for fear that (lest) he should catch a cold. (她把一条毛毯盖在孩子身上,以防他感冒。)
可见,此类虚拟语气比较容易接受,考试时只要认准了上面的那些字一般就不难作出准确选择。
就解题而言,考生要注意:1)A的位置往往安排干扰项,如使用must, may, might, could等类词进行干扰;2)句中往往省去should, 直接用否定词not + 原形动词的形式,以"迷惑"考生,例如:
The housemaster(男舍监)was very strict.He asked that we ______ television on week nights.
A. must not watch
B. not watch
C. should not have watched
D. not be watching
该题中的"ask"意为"要求",故是个"should型"虚拟式, 正确答案为B.
(4)在it is surprising, disappointing, a pity, a shame, no wonder, simply a miracle + 从句的结构中,表示惊讶、高兴或遗憾,例如:
It is surprising that she should look so miserable. (真是奇怪,她竟看上去如此不高兴。)
It is a great pity that you should miss such a good film. (你要是错过了这样好的电影那真是遗憾。)
2.were型虚拟式:
所谓were型虚拟式,就是借用行为动词过去时的某个形式以及be动词的"were"这个形式来表达某种虚拟的语气。
由于were型虚拟式主要用在if非真实条件句中,而且它是其他were型虚拟式句型的基础,所以我们先要搞清楚if非真实条件句。
(1) if非真实条件句:
条件句分为真实条件句和非真实条件句:
真实条件句是指真实的或可以实现的条件句,例如:If we work together, we are sure to finish the task in time. (如果我们大家一起努力,就一定能按时完成任务), 动词使用的是真实的时态和形式。
非真实条件句是指对已经发生过的事情,或对不可能发生或实现的事进行假设,例如:"如果当时有医生在,这个孩子就有可能得救了",显然,这是对已发生的事情的一种假设,该句的英语表达为:If there had been a doctor available, the child might have been saved.
为了便于理解和记忆,我们用表格形式加以归纳:
时间
动词形式
举例
过去
if条件句:had done / had been结果句:would have done / been If there had been a doctor available, the child might have been saved.
倒装:Had there been a doctor available, the child might have been saved
现在
if条件句:did / be动词用were结果句: would do (be) If I were you, I would accept his offer. (如果我是你的话,我就接受他的提议。)
倒装:Were I you, I would accept his offer.
If I knew the fact, I would tell you. (我要是知道,我就会告诉你)
不可以倒装
将来
if条件句:should do (be) / were to
结果句:would do (be) If it should rain tomorrow, we would stay at home. (一旦明天下雨,我们就呆在家里。)
倒装:Should it rain tomorrow, we would stay at home.
If he were to come this evening, I would ask him to help solve the problem. (要是他晚上会来,我就请他帮助解决这个问题。)
倒装:Were he to come this evening, I would ask him to help solve the problem.