愛華網(wǎng)whether, if用法區(qū)別總結(jié)
if,evenif,whether,unless,butfor…用法
whether和if通用，都表示“是否”的意思。一般來說，后者比較正式，在口語中前者常用來代替后者。但兩者有時具有不同的暗示。用whether時，正反兩面的選擇意義較強(qiáng)，問話人并不在意回答是肯定還是否定；而用if時，則比較強(qiáng)調(diào)單方面，即正面，問話人希望得到肯定的回答。另外，還要注意從以下六個方面的高頻考點(diǎn)：
一、whether和if都可以與ornot連用； 但whether和ornot寫在一起時，或在動詞短語后，只能用whether，不能用if。如：
二、在引導(dǎo)賓語從句時，應(yīng)注意：
1、表示“是否”時，兩詞都能引導(dǎo)賓語從句。
①Idon't know whether/if I will be able to come.我不知道我是否能來.
②She asked me whether/if I was interested in working forher.她問我是否有興趣為她工作。
③We'll be told tomorrow whether we should take the exam ornot.我們明天才知道是不是應(yīng)該參加考試.
④I asked him whether he had done all the workhimself or whether he had had any assistance.我問他這些工作都是他自己做的還是別人幫他做的.
⑤Iwonder if/whether you can examine him now．
( 注意: 在兩個供選擇的從句之間若用or字, 則須重復(fù)whether一字. )
注:⑴當(dāng)強(qiáng)調(diào)賓語從句并將其提前時只能用whether。
如:Whether I'll have time to go with you I am notsure.我很難說我們是否有時間跟你們一起去。
2、賓語從句移置句首時，用whether，不用if。
Whether it is trueor not， I can't say．
=I can't say whether/if itis true or not
3、賓語從句為否定形式時，通常用if，而不用whether。
Iasked Tom if Mary wouldn’tcome．
4、動詞discuss，decide, consider等后習(xí)慣上也常用Whether引導(dǎo)從句，不用if。
They discussed whether they should leave atonce.他們討論了是否應(yīng)該馬上離開。
We discussed whether the house should besold. 我們討論了這房子是否應(yīng)賣掉。
Wediscussed whether we should buy the gift forhim．
三、在下列情況下，只能用whether，不能用if。
1、與不定式連用時，只能用whether．
He can't decide whether to accept orrefuse．
2、在介詞后，只能用whether。
Everything dependson whether he isready．
Idon't care aboutwhether ornot it willrain.
3、在名詞后作同位語時，只能用whether。
Thequestion whether they ought to stop working was discussed among theworkers．
Ihave no idea whether he isthere．
4、引導(dǎo)主語從句時，只能用whether。
Whetherhe comes or not doesn't concern me．
5、引導(dǎo)表語從句時，只能用whether。
WhatMaria doesn't know is whether there will beenoughsnow．
6、當(dāng)whether和ornot連用時，只用whether不用if。如:
Idon’t know whether or not he will come.我不知道他是不是回來。
I'll be happy whether/if I get the job or not我能不能得到那份工作都一樣高興。注意：當(dāng)ornot放在whether引導(dǎo)的從句句尾，則可以用if來替換。
7、 當(dāng)whether和or 連用表示明確的選擇時，只用whether不用if。
He asked me whether I wanted to go there by train or bybus.他問我是想乘火車還是坐公共汽車去那里。
He hesitated about whether he should drive or take thetrain.他開車去還是坐火車去, 猶豫不決
注:whether 和or連用還可以引導(dǎo)讓步狀語從句,此時也不用if。如：We'll go on with the work, whether we canfind the necessary tools or not.
不管我們能否找到所需的工具,我們要把這件工作做下去。
Whether or not it rains / Whether it rains or not, we're playingfootball on Saturday.無論下不下雨, 我們星期六一定踢足球.
8、在動詞不定式之前，只能用whether，不能用if。
①The question is whether to go to Munich orVienna.問題是去慕尼黑還是去維也納.
②She doesn't know whether to get married now orwait.是否現(xiàn)在結(jié)婚或是等待她不知道。
③We were wondering whether to go today ortomorrow.我們弄不清是今天走還是明天走.
④I'm not sure whether to resign or stayon.我拿不準(zhǔn)主意是辭職還是留任.
四、if可引導(dǎo)條件狀語從句，譯作“如果”，whether可引導(dǎo)讓步狀語從句，譯作“不管、無論”。
If Iwere you，I would not buy．
Whether he agreesor not，I shall go there．
We'll go on withthe work, whether we can find the necessary tools ornot.不管我們能否找到所需的工具,我們要把這件工作做下去。
Whether or not it rains / Whether it rains or not, we're playingfootball on Saturday.無論下不下雨, 我們星期六一定踢足球.
五、whether和if均可用來引導(dǎo)主語從句，但if引導(dǎo)的從句不能位于句首。
Whether they win orlose is all the same to me. 他們是贏是輸於我都一樣.（此時whether不能換作if ）
It's doubtful whether there'll be any seats left.說不上還有沒有空座位了.(此句whether能換作if)
六、表語從句、同位語從句用whether引導(dǎo)不用if.
The doubt was whether you had broken the beautifulvase.疑問是你是否打壞了這只漂亮的花瓶。
Thequestion whether we'll build another lecture building hasn't beensettled.是否要另建一幢教學(xué)樓的問題還未決定。
七、強(qiáng)化練習(xí)：
1. The question has not been answered ____ Taiwan will be includedon the Olympic torch relay route.
A．thatB．whetherC．whichD．if
2. You have not yet answered my question _____ I can join in theparty tonight ornot.
A.whether B.ifC.thatD.which
3．— I d like to invite you to a party this evening.
— Thank you, but _____ I’ll be free I m not sure at themoment.
A.whileB.ifC.whenD. whether
4．---What are you anxious about?
---___________
A.If we succeed B.That we cansucceedC. Do we succeed D.Whether wecan succeed
5. Only when _____ the painting _____ decide ______the painting isworthbuying.
A.he sees, he can,whether B.does he see, can he,if
C. he sees, can he,whether D.sees he, he can,that
6. _____ English is his favourite subject
A. I askedhimifB. I asked him that whether C. I asked himthatD. I asked him which
7. _____ they’ll go to the Summer Palace ____ the weather.
A. If;dependsonB. Whether; depends upon C.Whether; dependedonD. If; depended upon
8.It isn’t quite _____ ______ he will be present at themeeting.
A. sure;whetherB. sure;ifC. certain;whetherD. certain; that
9. _____ the 2008 Olympic will be held in Beijing is not knownyet.
A.WhetherB.IfC.WheneverD. That
10. No one was sure _____ he would be asked to speak nextyear.
A.whenB.whetherC.whatD. how
11. It is still a question to us all _____ there is any livingthing in some other places in the space.
A.whetherB.whichC.whatD. where
12. I doubt _____ he will come here on time.
A.thatB.whetherC.whenD. where
13. The pointis not who said the words, _____ they are true ornot.
A.butwhetherB. andwhether C.buthowD. and how
14. “What did he ask you?” “_____ I would be late.”
A.ThatB.WhenC.WhereD. Whether
15. He treated all the people around him,______he knew or he didn'tknow,______.
A. if,friendlyB. whether, friendly
C. if, in a friendlywayD. whether, in a friendly way
16. At the meeting, we discussed _____ we should employ moreworkers.
A.ifB. whetherC.thatD.不填
Answers: BADDC ABCAB ABADD B
