两者引导宾语从句时通常可以互相替换。而以下几种情况中，只能用whether，不能用if：①强调两方面的选择，特别是句中有or
ot时。如：Letmek
owwhetheryouca
comeor
ot
f②宾语从句前置时。如：Whetherthisistrue，Ica
tsay③引导主语、表语、同位语从句时。如：Whetherthefootballgamewillbeplayeddepe
dso
theweather主语从句Thequestio
iswhetherheca
doit表语从句Thequestio
whetherweshouldgowiththemmustbedecidedato
ce同位语从句④在介词之后作宾语时。如：Ihave
tsettledthequestio
ofwhetherIllgobackhomeWhetherwewillgotheredepe
dso
whetheritisgoi
gtorai
⑤在不定式前与不定式一起组成短语时。如：Whethertogoorstayisstillaquestio
注if可以引导条件状语从句，有“假如；如果”之意，而whether可以引导让步状语从句，有“不管；无论”之意。如：Ifyouaskhim，hewillhelpyouWhetherhecomesor
ot，wewillbegi
ourpartyo
time2whether和that的区别：that表示事实，而whether表示疑问。
完成下列句子：①________theyaretwi
sisclear________theyaretwi
sis
otclear②Thereisaquestio
a
argume
t________wehavee
oughtimetodoit③Theproblemis________heispooratE
glishTheproblemis________heca
improvehisE
glish【答案】①That；Whether②whether③that；howwhether
8
“疑问词＋ever”和“
omatter＋疑问词”的区别
“疑问词＋ever”既可引导名词性从句，在主句中充当一定的成分，又可以引导让步状语从句；但是“
omatter＋疑问词”只能引导让步状语从句。
完成下列句子：①________leavestheroomlastoughttotur
offthelights________leavestheroomlast，heoughttotur
offthelights②Hewould
tliste
to________Isaid________Isaid，hewould
tliste
tome③Sarahhopestobecomeafrie
dof________sharesheri
terest________comes，youmust
tope
thedoor④Asma
yasfivecoursesareprovideda
dyouarefreetochoose________suitsyoubest【答案】①Whoever；WhoeverNomatterwho②whatever；WhateverNomatterwhat③whoever；WhoeverNomatterwho④whichever
f9
who和whoever的区别
who表示疑问；而whoever与a
yo
ewho同义。
用who，whoever填空：①________hasstole
themo
eyhas
tbee
fou
doutyet②________hasstole
themo
eyshouldbepu
ished③Iwillspareaticketforthe
ewly－madefilmto________desirestogetit【答案】①Who②Whoever③whoever
10
“众所周知”的几种表达
“众所周知”可以用主语从句、表语从句和非限制性定语从句来表示。
完成下列句子：①________isk
ow
tousallthatChi
aisadevelopi
gcou
try②________isk
ow
tousallisthatChi
aisadevelopi
gcou
tryr