If和whether的区别含讲解+习题+答案

1、whetherif和whether都可译为 "是否",二者引导宾语从句时通常可以互相替换whether. 例如： Ask if/whether he plans to come to the meeting.能用 whether:?1 .强调两方面的选择，特别是句中有or not时.如：？Let me know whether you can come or not.?2 .宾语从句前置时.如：?Whether this is true, I can't say.?3 .引导主语、表语、同位语从句时.如：？Whether the football game will

2、 be played depends on the weather.The question is whether he can do it.（表语从句） ?The question whether we should go with them must be decided at once.4 .在介词之后作介词的宾语时.如：?，口语中多用if代替 而以下几种情况中，只(主语从句)？(同位语从句)？Ihaven'tsettledthequestionofwhetherI'llgobackhome.?5 .在不定式前与不定式一起组成词组时.如：？Whethertogoorsta

3、yisstillaquestion.?6 .在discuss,decide等动词后作宾语时.如：?Wediscussedwhetherweshouldgotherebyplane.?值得注意的是：if还可以引导条件状语从句，是'"假如；如果"之意，而whether可以引导让步状语从句，是"不管；无论"之意.如：?Ifyouaskhim,hewillhelpyou.?Ishallgo,whetheryoucomewithmeorstayathome.?一、if或whether引导宾语从句时，作“是否"讲，常放在动词ask、see、say、

4、know和findout等后面.一般情况下，两者常可换用，在口语中多用if.如：?例1Nobodyknowswhether(if)itwillraintomorrow.没有人知道明天是否下雨.？例2Lucyaskedwhether(if)theyhadacottonsweater.露西问他们是否有棉制的羊毛衣.'二、if或whether引导宾语从句时，要注意三个方面，即连词、语序和时态.?1 if或whether不能和that或其它连词(副tW同时使用，也不能省去.如：?例3我不知道他今天是否会来.?误Idon'tknowthatif(whether)hewillcomeher

5、etoday.?正Idon'tknowif(whether)hewillcomeheretoday.?例4他走过来看看猫是否出了毛病.?误Hecametoseewhatif(whether)therewaswrongwithhiscat.?正Hecametoseeif(whether)therewaswrongwithhiscat.?2 if或whether引导的宾语从句时，虽具有疑问意义，但从句语序应用陈述句语序.如：?例5Didyouknowthewaytothehospital?Theoldwomanaskedme.?Theoldwomanaskedme.if(whether)I

6、knewthewaytothehospital.老妇人问我是否知道去医院的路.?3 if或whether引导的宾语从句应和主句的时态保持一致.即主句为一般现在时，从句用任一种时态；主句为一般过去时，从句则用过去时中的任一种时态.如：?例6Idon'tknowif(whether)hehascomehere.我不知道他是否来过这儿.？例7Tomaskedif(whether)Ihadreadthebook.汤姆问我是否看过这本书.？三、if和whether的区别：？1在动词不定式之前只能用whether.如:例8Ican'tdecidewhethertostay.我不能决定是否留

7、下.？2在whetherornot的固定搭配中.如：?例9Iwanttoknowwhetherit'sgoodnewsornot.我想知道是否是好消息3在介词后，只能用whether.如：?例10Hisfatherisworriedaboutwhetherhelosehiswork.他的父亲担心是否会失去工作.？4宾语从句放在句首表示强调时，只能用whether.如：?例11Whethertheycanfinishtheworkontimeisstillaproblem.他们是否能准时完成这项工作还是个问题.?5用if会引起歧义时，只用whether.如：?例12Couldyoutel

8、lmeifyouknowtheanswer?这句话有两种意思：“你能告诉我是否知道答案吗？”或“如果你知道答案，请告诉我，好吗？”.如用whether可避免歧义.if和whether专题1) Idon'tcareyourcarbreaksdownornot.2) Thisdependsuponwearedeterminedtodoit.3) Itdependsonheisready.4) Iamnotinterestedinyou'llcomeornot.5) Wehaven'tsettledthequestionofwe'llrenewoursupplieso

9、fcoalforfactory.6) Hedoesn'tknowtostayornot.7) IamnotsureI'llhavetimetogowithyou.8) Shedoesn'tknowtogetmarriednoworwait.9) Idon'tknowornottheywillcomeforourhelp.10) Wediscussedweshouldmakeachangeinourplan.11) Heconsideredheshouldn'ttellherthesecret.12) Itisunknownhewillcome.13) I

10、don'tknowtheywillcometohelpus.14) Iamnotcertainthetrainwillarriveontime.15) thenewsistrueremainsaquestion.16) Whatwewanttoknowishewillcometospeaktoustomorrow.17) Thequestionistheycantakeouradvice.18) Letmeknowyoucan'tmeetmeatJacksonandThroopStreetsWednesdayafternoonattwoo'clock.19) Wewer

11、ediscussingweshoulddiscussthebusinesswiththem.20) Thequestionwe'llbuildanotherlecturehasn'tbeensettled.21) Thequestionhe'llcomeisunknown.22) Tellmeitisnotgoingtorain,please.23) Idon'tcarehedoesn'tshowup.24) Pleaseletmeknowyouintendtocome.25) LetmeknowhehasleftforShanghai.1) if/whether2) whether3) whether4) whether5) whether6) whether7) whether/if8) wh