详解英语名词性从句的正确应用

that与what的混用：

1.Thattheyaregoingtodiscussatthemeetingishowtoincreasefoodsupplyintheworld.(错误)

Whattheyaregoingtodiscussatthemeetingishowtoincreasefoodsupplyintheworld.(正确)

注：that在引导名词性从句时本身没有意义，也不在从句中充当任何成分；而what则表示“什么”“……的东西或事情”，在从句中充当主语，宾语或表语等。上句中的what应充当discuss的宾语。

if与whether的混用：

2.IfwewillvisittheGreatWalltomorrowhasnotbeendecidedyet.(错误)

WhetherwewillvisittheGreatWalltomorrowhasnotbeendecidedyet.(正确）

注：if与whether引导宾语从句时往往可换，但在下面情况时常使用whether：作介词的宾语时，见例①；在从句中提出两种选择时，见例②；从句提前时，见例③；引导主语从句，表语从句及同位语从句时，见例④。

①IworryaboutwhetherIhurthisfeelings.

②Shewasn’tsurewhethersheshouldlaughorcry.

③WhetherhewillcomeornotIdon’tquiteknow.

④Whatmanypeopleareworriedaboutiswhetherwewillbeabletobuildabetterfuture.

Wehavesomedoubtwhethertheycancompletethetaskontime.

that与because的混用:

3.(1)Thereasonwhyhewaslateforschoolwasbecausehegotuplate.(错误)

Thereasonwhyhewaslateforschoolwasthathegotuplate.(正确)

⑵Whyfarmlandhereisbeinglostisbecausefarmershavecutdowntoomanytreesinrecentyears.(错误)

Whyfarmlandhereisbeinglostisbecausefarmershavecutdowntoomanytreesinrecentyears.(正确)

注:reason作主语时引导的表语从句或why引导的名词性从句时常用that不用because.

忽略连词that:

4.TheseoldlanguagesarenowthreatenedandmaydisappearisaseriousmattertothepeopleinBritain.(错误)

ThattheseoldlanguagesarenowthreatenedandmaydisappearisaseriousmattertothepeopleinBritain.(正确)

注：that在引导宾语从句时常常可省，但在下面情况时不可省去：宾语从句不止一个时，见例①；宾语从句与主句之间有插入语时，见例②；宾语从句为一个主从复合句时，见例③；引导主语从句，表语从句或同位语从句时，见例④。

①Theycomplain(that)theyhavetoworkfrommorningtillnight,thatitishardtoearnmoney,thattheyarebullied(欺负)bythepolicemen,orthatthecorporationleadersareseatedlazilyandenjoythefruitsofothers’work.

②Theteachersaid,pleasantlyandfirmly,thatwemustovercomethedifficulties.

③Webelievethatifweworkharder,IwillpasstheNationalCollegeEntranceExamination.

④Thetroubleisthatshehaslosthisaddress.（表语从句)

WordcamethatChinalauncheditsfirstmannedspaceshiponOct.15,2003.（同位语从句）

nomatterwho\what\which\how\where…与whoever\whatever\whichever\however\wherever…

5.Nomatterwhobreakstheruleswillbepunished.（错误)

Whoeverbreakstheruleswillbepunished.（正确)

注：whoever,whatever,whichever,however,wherever等连词可以引导名词性从句也可引导让步状语从句，而nomatterwho\what\which\how\where…只能引导让步状语从句。例如

Nomatterhowgreatthedifficultyis,weoughttokeepon.

Or:Howevergreatthedifficultyis,weoughttokeepon.

相似句型的混淆:

6.Asisknowntoallthatscienceplaysanimportantpartinthedevelopmentofindustryandagriculture.（错误)

Asisknowntoall,scienceplaysanimportantpartinthedevelopmentofindustryandagriculture.（正确)

Itisknowntoallthatscienceplaysanimportantpartinthedevelopmentofindustryandagriculture.（正确)

注：as作为关系代词引导的非限制性定语从句位于主句之前时，从句与主句之间要用逗号隔开。It作为形式主语将that引导的主语从句后置时，that常常不能省。