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 本文来源：https://www.wddqw.com/doc/e8aa0e44306c1eb91a37f111f18583d049640fb1.html