（整理版高中英语）师范大学附属北师大高一英语《Unit4》语法.doc

省师范大学附属北师大版高一英语Unit4语法练习讲评Teaching procedure1. wish后面用虚拟语气，表示与过去事实相反用过去完成时。Wish + didHad doneCould/Would do2.条件句表示与过去事实相反，主句用过去将来完成时，从句用过去完成时。 If - clauseMain clause 真实条件 If do/does  will 虚拟条件 If did/were Would/could/should/might do Had done Would/could/should/mightHave doneShould do/did/were to do Would/could/should/might do3.as if后面是真实情况，不虚拟。在as if/as though引导的状语从句中，谓语动词多用倒退一个时间段的方式来 The man speaks as if he were a foreigner.as if/as though从句中不一定都要用虚拟语气。如果情况真实性、可能性很大，就要用正常时态来描绘。It looks as if it is going to rain.天看起来象要下雨。4.lain是lie的过去分词，表示“躺。Lie lied lied 说谎Lie lay lain 躺着Lay laid laid放置，下蛋5.could have done表示“本来可以。Should/may.have done 本。却但是must have done 只表示过去肯定做过6.but for表示“要不是的话，通常与虚拟语气搭配使用。 7.in advance表示“事先，表示与过去事实相反的虚拟语气。 8.suggest后面的宾语从句用sb. should do的形式。should可以省略。在suggest,propose,demand,request,require,order,insist等动词后的宾语从句中，谓语为“ (should) do形式。I suggest/propose/demand/request/require/order/9.would rather的宾语从句用sb. did的形式。10.It is time后面的定语从句用sb. did的形式。“It is (about/high) timethat从句，that从句的谓语用一般过去时或“should do It is high time he started = It is high time he should start11.这虚拟语气的倒装形式如果条件句中有were,had,should 等助动词，可将if省略，把were,had或should置于句首,来表达以if引导的条件句的相同意思。Should it rain/were it to rain tomorrow,the sports meet would be put off.12.在虚拟语气中，不管什么人称，be动词都要用were的形式。