专业英语四级考试语法

名词性从句中的虚拟主语从句(itis+adj./p.pthat)同位语从句(The+n.That)表语从句(n.+bethat)省略if的虚拟法（倒装）(1)虚拟语气中如果从句引导词if/whether省略，从句中需要倒装，提前助动词(系动词）或情态动词。E.g.Ifitshouldraintomorrow,wewouldnotbeabletohavethesportsmeeting.=Shoulditraintomorrow,weshouldnotbeabletohavethesportsmeeting.省略if的虚拟法（倒装）(2)E.g.whetherit(may)befineorrainy,wewouldhavethesportsmeeting.=Beitfineorrainy,wewouldhavethesportsmeeting.Ifshehadbeengivenmoreinformation,shecouldhaveansweredthequestions.=Hadshebeengivenmoreinformation,shecouldhaveansweredthequestions.总结虚拟语气的动词标志insist,suggest,require,request,demand,propose,prefer,maintain,move,urge,recommend,command,order等动词表建议、愿望时，其后宾语从句中谓语动词要用虚拟语气。Should+Vwish其后宾语从句中谓语动词要用虚拟语气。{虚拟语气的名词标志1“necessity”或“suggestion”等名词后面的表语从句或同位语从句中的谓语动词要用虚拟语气。2名词word表“命令”时，其后主语从句、表语从句或同位语从句中，谓语动词需用虚拟语气(should)+V。3wish作名词时其后主语从句，表语从句或同位语从句中，谓语动词需用虚拟语气(should)+V。虚拟语气的形容词标志Itis+adj.that句型中出现形容词如necessary,important,vital,decisive,critical,crucial,urgent,strange,desirable,advisable,disappointing,或过去分词充当的形容词如suggested,proposed,advised,demanded,requested,required等时，that句中用sshhoouulldd++VV表示虚拟。虚拟的介词标志Butfor相当于ifithadnotbeenfor。Butforherhelp,Iwouldhavelostmyway.Without,intheabsenceof等组成的短语可相当于一个虚拟的条件从句。Withoutthelightandheatofthesun,whatwouldbecomeofalltheanimalsonearth?Intheabsenceofwater,plantswouldnotgrowwell.Under…condition,也可相当于一个虚拟条件从句。Undermorefavorableconditions,wewouldhavemademoreachievements.错综时间的虚拟条件状语从句中谓语动词的形式可与主句中谓语动词的形式不“配套”，即错综时间的虚拟。IfhehaddoneasIhadsuggestedthen,hewouldn’tberegretfulnow.Iftheyhadn’tfoundusthen,wewouldstillbemissingonthesea.IfIhadn’tmadesufficientpreparationfortheexamthen,Iwouldn’tbeincollegenow.虚拟和事实（前虚拟后事实）标志:butE.g.Iwouldhavegonetothepartywithyou,butIwastoobusy.=IfIhadn’tbeentoobusy,Iwouldhavegonetothepartywithyou.（前事实后虚拟）标志:otherwiseE.g.Iwastoobusythen,otherwiseIwouldhavegonetothepartywithyou.MoreInformationwas(were)+tohavedone（不定式完成式）表示“原来想做而未做”后面通常but…（陈述语气）。E.g.Iwastohavearrivedhomeontime,butmycarwasheldupbyabadtrafficjam.hadhoped表示过去未实现的愿望，其从句中谓语动词要用虚拟would+V。E.g.Ihadhopedthathewouldagreetolendmethemoney.(倒装）带否定意义的副词置于句首时(1)带否定意义的词置于句首时，主谓语需要倒装。Rarelydoeshegotothemovies.Notforamomentdidhedoubtthetruthofherhonesty.LittledoIknowaboutthemeaningofthisproverb?NeverbeforethenighthadIfelttheextentofmypower.含有否定词的介词短语在句首含含有有否否定定词词的的介介词词短短语语在在句句首首时时，，句句子子主主谓谓倒倒装装。。这类介词短语包括：innocase,atnotime,innoway,bynomeans,onnoaccount,innosense,undernocircumstances,等等。意思为“决不，在任何情况下都不。”“Only+状语”置于句首时的倒装(1)“Only+状语”置于句首时，主谓语需要倒装。1)OnlybypracticingalotoutsideclasscanwespeakEnglishfluently.2)OnlywhenIsawhimdidIrememberthatIpromisedtobringhimagift.3)OnlythendidIknowthatIwaswrong.notonly位于句首时的倒装句首是notonly且连接分句结构时，引起局部（部分）倒装。Notonlydidweloseourmoney,butwewerealsoindangeroflosingourlives.Notonlycanhesingverywell,buthecanalsoplaysomemusicalinstrumentveryskillfully.neither，nor表示“也不”时的倒装(1)句首是neither，nor表示“也不”时，主谓语需要倒装。Icouldn’tsolvetheproblem,neither/norcouldmybrother.=Icouldn’tsolvetheproblem.Mybrothercouldn’t,either.Ididn’tgotoschool,nordidMary.=Ididn’tgotoschool.Marydidn’t,either.so表示“也是，同样”时的倒装句首是so表示“也是，同样”时，主谓语需要倒装。Copperisagoodconductor;soissilver.Johnfailedintheexam;sodidMark.Hetakespartinsportsactivities,sodohisclassmates.IhavebeentotheTempleofHeaven,sohasshe?平衡倒装There+be或其它不及物动词come，go，happen，occur，stand，exist等结构中，为避免句子头重脚轻，平衡倒装。Therestandsanoldhousethatisbeingpulleddown.Thereexistedahostilerelationshipbetweenthetwofamilies.Therearemanyhobbiesinvolvingthecreativityofaperson.Such/so…that句型中的倒装Such/so…that句型中such+名词或so+形容词，副词等位于句首时，主句中主谓倒装。Sobadlywasheinjuredintheaccidentthathehadtostayinthehospitalfortreatment?SoexcitedwasIthatIdidn’tknowwhattosay.比较状语从句中的倒装than引导的比较状语从句中，主从句谓语趋向中间以达到平衡，此时从句要求主谓倒装。Nowadays,withtherapiddevelopmentofscienceandtechnology,manislesslimitedbynaturethanwerehisforefathers/ancestors.表频率的状语至于句首倒装表频率的状语至于句首，倒装。Manyatimehashegivenussoundadvice?Twiceaweekdoeshegotovisithisgrandparents?Morethanoncehaveweheardhimmakesuchpromises?As,though让步状语从句中倒装在以as，though引导的让步状语从句中，从句常用倒装语序，把表语或状语提前。（名，形，付，动词）Childthatheis,hecandistinguishbetweenrightandwrong.Intelligentas/thoughyouare,youshouldbemodest.MuchasIadmirehim,Idon’tthinkheisperfect.Tryasshedid,shefailedagain.虚拟语气中的倒装虚虚拟拟语语气气中中省省略略““iiff””或或““wwhheetthheerr””时时的的倒倒装装。。Wasitlefttometochoose,Ipreferthelattertotheformer.Haditnotrainedsoheavily,wewouldhavevisitedtheSummerPalaceyesterday?Bewerichorpoor,weshouldhaveourowndignity.副词至于句首Here、there、in、out、up、down等表示方位的副词至于句首时，主谓需要倒装。Herecomesthebus.Downjumpedthelittleboyfromthebridge.Hereit(指thebus)comes.Theretheywent.就近/毗邻一致原则(1)There或here引起的句子中主语不止一个时，谓语就近一致。就近/毗邻一致原则(2)由or、either…or或neither…nor、notonly、…butalso、not,…But…等连接的两个主语谓语就近一致。谓语动词多用单数的情况（1）Manya/Morethanone所修饰的名词作主语时谓语动词多用单数。Manyabravesoldierhasdiedinthatbattle.Morethanonequestionhasbeenraisedinthelecture.谓语动词多用单数的情况（2）Either/neither做主语通常作单数看待，谓语动词多用单数。Eitherofthemethodsiseffective.Neitheroftheroadsleadstothetown.谓语动词多用单数的情况（4）主语中包括“and”时，若表示一个单一概念，谓语动词应做单数。加：(and连接两个单数名词前面如有each、every，manya，no等)Thepoetandwriterhascome.AllworkandnoplaymakesJackadullboy.Everymanandwo