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请问if里的那个条件句和虚拟语气是什么啊

来源:学生作业帮 编辑:作业帮 分类:英语作业 时间:2024/11/07 17:01:07
请问if里的那个条件句和虚拟语气是什么啊
是不是条件句就是虚拟句啊?有什么区别啊?在时态上有区别吗?
随着说话人意图的不同,动词需要用不同的语气.英语中的语气分为陈述语气、祈使语气和虚拟语气三类.
英语中的虚拟语气可分为对现在、过去和将来的虚拟以及表达祝愿、坚决、决定、要求、命令等主观愿望的虚拟.
1.表示假设的虚拟语气:主要用于对现在、过去和将来事实相反的假定.
A 与现在事实相反的虚拟语气
虚拟主句中用should/would/could/might+动词原形,条件从句中谓语动词用过去式.
1) If everyone knew first aid,many lives would be saved.如果每个人都懂得急救知识,许多生命就会得以挽救.
2) If I were 20 years younger,I would start all over again.如果再年轻20岁,我会从头再来.
B 与将来事实相反的虚拟语气
虚拟主语的谓语动词用should/would/could/might+动词原形,条件从句的谓语动词又三种形式,即should do,were to do和动词的过去式.
1) If it rained tomorrow,our plan would be put off.如果明天下雨,我们的计划救得推迟.
2) If the sun were to rise in the west,I would not change my mind.即使太阳从西边出来,我也不会改变主意.
C 与过去事实相反的虚拟语气
虚拟主句用should/would/could/might+have+过去分词,条件从句中的谓语动词用过去完成式.
If you had worked hard,you would have easily passed the final test.如果当时你努力的话,你就会轻松通过期末考试.
D 省略if 形式的虚拟语气
if虚拟条件句中有should,had 或were时,if可省略,从句中主谓要倒装.
Had I worked hard,I would have surely succeeded.如果我当时努力学习的话,我当然会成功.
E 混合虚拟语气
有时主句与从句所指的时间不一致,这叫错综虚拟语气或混合虚拟语气,它要求主、从句的时态根据时间概念来确定.
If it had rained last night,it would be very cold today.如果昨天夜间下雨了,今天会很冷的.(从句是对过去的假设,主句是对现在的假设.)
F 含蓄虚拟语气
有时假设的条件不通过条件从句表达出来,而隐含在某些介词短语中,如without,but for 等,或隐含在上下文里,这种句子要用含蓄虚拟语气.
1) Without music,the world would be a dull place.=If there were no music,the world would be a dull place.
2) But for your advice,I would have failed.= If you hadn’t given me advice,I would have failed.
2.表示责备及批评的虚拟语气
“should/ought to/could/may/might+have+过去分词” 表示 “过去应该做而未做到”的虚拟语气,该结构的否定形式则表示“过去不该做的事却做了”,是一种委婉的责备“,语气最强的是should,最弱的是might.
A 表示委婉批评
用于委婉批评的结构为 could/may/might have done,常译为“本可以做得更...一些”、“本该...而...”.
You’ve made a few mistakes.You might have been a little bit more careful.你犯了几个错误.你本该更小心一点.
B 表示强烈责备
表示强烈责备得常用结构为should/ought to have done,译为“本应该做得更...一些,结果...”.
You should have told me earlier that you weren’t able to come.你本应该早点告诉我你不能来的.(暗含结果我在这等了这么常时间.)
C 表示本没必要
“needn’t+habe+过去分词”结构,表示“做了没必要做的事情”.
You need’t have told him.He has already known about it.你当时没必要告诉他,他早已经直到了.
3.表示“建议、命令、要求、坚决”等的虚拟语气
具有上述意义的动词的宾语从句常用“(should)+动词原形”结构.英国英语中常用should,美国英语中一般不用should,而直接用动词原形.该类动词主要有demand,desire,require,request,propose,suggest,command,order,decide,insist,persist 等.
1) I suggest you (should) have enough sleep.我建议你应睡足觉.
2) The people present at the meeting all persisted that the river not be polluted again.所有与会者都强烈坚持河流不能再被污染了.
4.表示祝愿的虚拟语气
表示祝愿时常用动词原形或“May+主语+动词原形”结构.
1) May you succeed!
2) Long live the people!人民万岁!