Revision:定语从句的功用:相当于一个形容词,修饰一个名词或代词(即先行词)。常紧跟在先行词后,作定语用。如:Idon’tlikethemanwhowearsabeard.宾语从句的功用:相当于一个名词,作及物动词、形容词或介词后的宾语表语从句的功用:如:Idon’tknowwhereIcangotsomuchmoney.Itdependsonwhetherwehaveenoughmoney.Iamsurethathewillcomethisafternoon.相当于一个名词,作连系动词如:be,look,taste,seem等后的表语。一、表语从句的定义:表语从句在复合句中作主句的表语。表语从句和主语指同一内容,它对主语进行解释、说明,使主语的内容具体化。二、表语从句的表现形式1.由从属连词引导。如:“that”,“whether”Thequestioniswhetherweshouldaskthemforhelp.Thetroubleisthathehasneverdonetheworkbefore.2.由连接代词引导。如:“what”“who”“whom”“whose”“which”Guilinisnotwhatitusedtobe.Whatshewantstoknowiswhichdresssheshouldbuy.3.由连接副词引导。如:“when”“why”“where”“how”“because”ThatiswhereLuXunusedtolive.Thatiswhyhedidn’tpasstheexam.4.另可由asif,asthough引导。如:Itlooksasifitweregoingtorain.表语从句两大要素:1.除that外的所有引导词都有自己的意义。2.除that,whether外的所有引导词都须在从句中充当相应的成分。一些引导词的用法(一)that在表语从句中,又。Thefactisthathehasn’tyetrecoverfromillness.Thereasonwhyhehastogoisthathismotherisillinbed.既不充当成分没有意义比较在定语从句中的用法。TherearesomefilmsthatI’dliketosee.SheistheonlyoneamongusthatknowsFrench.结论:that在引导定语从句时,指事物,也可指人,在从句中作主语或宾语,作宾语时常可省略。一些引导词的用法(二)What在表语从句中充当表示.1.Thequestioniswhatcausedtheaccident.2.Thatmountainisnolongerwhatitusedtobe.3.Whathetoldyouwaswhathadbeendiscussedatthemeeting.主语、宾语或表语什么,什么样子,或所……的(人或事)另:what不引导定语从句一些引导词的用法(三)Which在引导表语从句时,常充当_____________表示。如:Ireadaboutitinsomebookoranother,butwhatIdon’tknowiswhich(book)itis.比较在定语从句中的用法。Chinaisacountrywhichhasahistoryof2000years.Adictionaryisabookwhichgivesthemeaningofwords.定语,表语其中哪一个结论:which在引导定语从句时,指事物,在从句中作主语或宾语,作宾语时常可省略一些引导词的用法(四)当主句的主语为reason,或者是why由引导的从句时,与它们相关的表语从句用_________,而不能由_______引导;because引导表语从句时只能用于___________________________句型中.如:ThereasonwhyIwaslatewasthatImissedthetrain.Iwaslate.It/That/ThiswasbecauseImissedthetrain.that来引导becauseIt/That/Thisis/wasbecause…一些引导词的用法(五)•whether在表语从句中表,但不充当句子的成分。if引导表语从句.如:Whatthedoctorreallydoubtsiswhethermymotherwillrecoverfromtheseriousdiseasesoon“是否”不能1.LiLeiisnowinanewjacket.HelooksasifhewereanAmericanboy.2.Thegirlisgivingusavividdescriptionofthemoon.Itseemsasifshehadbeentothemoonmanytimes.3.Itlooksasifitmightrain.4.Thecloudsaregathering.itlooksasifitisgoingtorain.一些引导词的用法(六)由asif,asthough引导表语从句时要注意语态.若从句表示与现在事实相反,谓动用,与过去事实相反用或表示将来的可能性不大,则用.一般过去式(be用were)had+p.p.Would(might,could)+v原