whether和if均可用来引导宾语从句.doc

whether和if均可用来引导宾语从句，表示“是否”，如：
don't know whether/if I will be able to come.我不知道我是否能来.
She asked me whether/if I was interested in working for her.她问我是否有兴趣为她工作。
但也有差别：
1、 whether可以与or 或or not连用，而if不可以，如：
He wondered whether he should wait or go .
I don’t know whether he will come. or not。
2 介词之后用 whether , 不用 if .
It depends on whether you will agree .
3 不定式前面用 whether 不用 if .
I wonder whether to stay here .
5 当从句或主句放于句首时，用 whether ，不用 if .
Whether this is true or not , I can't say .
Whether I'll have time to go with you I am not sure
6 引导表语从句用 whether ， 不用 if .
The problem is whether we should go home or not

8 作 discuss 的宾语，用 whether ， 不用 if .
They are discussing whether they should open the door
9、当表示“如果”时用 if,而不用whether
强化练习：
1. The question has not been answered ____ Taiwan will be included on the Olympic torch relay route.
A．that B．whether C．which D．if
2. You have not yet answered my question _____ I can join in the party tonight or not.
A. whether B. if C. that D. 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 the moment.
A. while B. if C. when D. whether
4．---What are you anxious about?
---___________
A. If we succeed B.That we can succeed C. Do we succeed D.Whether we can succeed
5. Only when _____ the painting _____ decide ______the painting is worth buying.
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 asked him if B. I asked him that whether C. I asked him that D. I asked him which
7. _____ they’ll go to the Summer Palace ____ the weather.
A. If; depends on B. Whether; depends upon C. Whether; depended on D. If; depended upon
8.It isn’t quite _____ ______ he will be present at the meeting.
A. sure; whether B. sure; if C. certain; whether D. certain; that
9. _____ the 2008 Olympic will be held in Beijing is not known yet.
A. Whether B. If C. Whenever D. That
10. No one was sure _____ he would be asked to speak next year.
A. when B. whether C. what D. how
11. It is still a question to us all _____ there is any living thing in some other places in the space.
A. whether B. which C. what D. where
12. I doubt _____ he will come here on time.
A. that B. whether C. when D. where
13. The point is not who said the words, _____ they are true or not.
A. but whether B. and whether C. but how D. and how
14. “What did he ask you?” “_____ I would be late.”
A. That B. When C. Where D. Whether
15. He treated all the people around him,______he knew or he didn't know,______.
A. if, friendly B. whether, friendly
C. if, in a friendly way D. whether, in a friendly way
16. At the meeting, we discussed _____ we should employ more workers.
A. if B. whether C. that D.不填

Answers: BADDC ABCAB ABADD B