虚拟语气在if条件从句中的用法

虚拟语气在if条件从句中的用法在if 引导的虚拟条件句中，若表示与现在事实相反，从句谓语用“动词过去式（be 的过去式用were ）,主句谓语用“would(should, could, might)+have+过去分词”；若表示与将来事实相反，从句谓语用“动词过去式（were to +动词原形，should+动词原形）”，主句谓语用“would(should, could, might)+动词原形”。若把从句中were, should 或had移到句首，可省略从句的连词 if 并使用倒装语序. If my lawyer _here last Saturday ,he _me from going.(NMET89)A. had been ;would have prevented B. had been ; would preventC. were ;would preventD. were;would have prevented-If he _,he _that food. -Luckily he was sent to the hospital immediately.(MET93)A. was warned ;would not takeB. had been warned ;would not have takenC. would be warned; had not takenD. would have been warned; had not taken I didnt see your sister at the meeting .If she _,she would have met my brother.(NMET94)A. has come B. did come C. came D. had come_it rain tomorrow, we would have to put off the visit to the Yangpu Bridge.(1994,上海)A. Were B. should C. Would D. Will2考查通过上下文或介词短语表示虚拟条件的虚拟语气的用法在英语中，有时假设的条件不是通过if 条件句表达出来，而是通过上下文或without, but for 等介词构成的短语表达，其谓形式要根据所假设的时间，与if 从句所表达的时间对应，确定主句谓语形式。考例Without electricity human life _quite different today.(NMET91)A. is B. will be C. would have been D. would be I told Sally how to get here ,but perhaps I _for her .(NMET94)A. had to write out B. must have written it out C. should have written it out D. ought to write it outwithout the air to hold some of the suns heat, the earth at night_, too cold for us to live.(1997,上海)A. would be freezing cold B. will be freezing coldlyC. would be frozen cold D. can freeze coldly3.考查虚拟语气在as if 引导的方式状语或表语从句中的用法As if 引导的方式状语或表语从句，谓语动词用“一般过去式”表示与现在事实相反；用“would(might, could)+动词原形”表示与将来事实相反。The two strangers talked as if they _friends for years.(1993,上海) A.should be B.would be C.have been D.had beenWhen a pencil is partly in a glass of water, it looks as if it _.(NMET95)A.breaks B.has broken C.were broken D.had been broken4.考查虚拟语气在wish 后面宾语从句的用法Wish 后面的从句，谓语用“过去式”表示现在不能实现的愿望；用“had+过去分词”表示过去没有实现的愿望；用“would(should,could) +动词原形”表示将来不能实现的愿望。考例 I wish I_you yesterday.(Met”88)A. seen B.did see C.had seen D.were to see5考查虚拟语气用于宾语从句的用法。在及物动词insist ,order ,require ,demand, command等后面，宾语从句所说的是尚未发生的事，所以谓语要用与将来事实相反的虚拟语气，即“should+动词原形”表达。其中should 可以省略。考例（11）The guard at the gate insisted that every body _the rules.(MET85)A. obeys B. obey C. will obey D. would obey(12) The officer ordered that everybody _part in the campaign. (1986.上海)A. take B. taken c. took D. will take 答案:1-5 ABDBD 6-10 CADCC 11-12 BA 1 Elize remembers everything exactly as if it _yesterday.(2006全国卷一)A. was happening B .happens C. has happened D. happened 解析:D. 考察虚拟语气.as if 引导的从句通常用虚拟语气.又因 remember知 与现在事实相反,因此用一般过去时.2. _fired, your health care and other benefits will not be immediately cut off. (2006湖北)A. would you be B. should you be C. could you be D. might you be 解析:B考察虚拟语气的倒装.if 引导的条件状语从句,如果用虚拟语气,可以把if 省略,将助动词were, had 或should 提前,构成倒装.3. I was on the highway when this car went past followed by a police car. They _at least 150 kilometers an hour.(2005 重庆)A. should have been doing B. must have been doing C. could have done D. would have done 解析:B 考察虚拟语气.表推测4. He paid for a seat, when he _have entered free.(2005 山东)A. could B. would C. must D. need 解析: A. 考察虚拟语气情态动词的用法5. Mr.White _at 8:10 for the meeting, but he didnt show up.(2004全国卷三)A. should have arrived B. should arrive C. should have had arrived D. should be arriving 解析: A 本题考察虚拟语气及责备的用法. Should have done 结构,表过去原本该做而没做的事. 高考预测：1. What would have happened if you_her child ?A.hadnt helped   B. couldnt help  C. wouldnt help  D. didnt help解析：A表示过去时间的虚拟是条件从句，用过去完成时，主句用would (should)+have + 动词原形。2. If I _with her last summer, I _with her now .A. worked -am getting on very wellB. had worked -will get on very wellC. had worked -would have got on very wellD. have worked -will get on very well.解析：B。本题是混合式虚拟语气。主句是对现在时间的虚拟。3. The boss ordered that he _the work at once A. starts B. will start C. would start D. start 解析：D order, suggest 等词后的宾语从句，要用虚拟语气，构成为should +v, should可以省略。4. The little heros pale face suggested he _dead.A. is B. was C. should be D. be 解析；B 不作建议讲时，宾语从句谓语不用虚拟语气。5._I known it, I should have told him .A. have B. had C. having D. If 解析：B 这是一个与过去事实相反的虚拟语气，如非真实性条件句谓语含had ,should ，were 时，可将这些词提到句首，省去if.6.If you had gone to a doctor, you _all right now.A. would not come B. might not come C. should not come D. could not come 解析：C 表示与将来事实相反的虚拟语气句。