巧记whether与if异同

1、【精品文档】如有侵权，请联系网站删除，仅供学习与交流巧记whether与if异同.精品文档.巧记whether与if异同主从表从同位从，if不用whether用；discuss和介词后，whether引宾从；不定式、or not后在跟，whether独能显神通；宾从若是否定句，if发挥其功用；避免歧义要慎重，其他情况可换用。一、引导主语从句，常用whether(1)Whether the meeting will be held is uncertain会议是否召开还不能确定(2)It is unknown whether he will come他是否来还不知道。3.Whether well

2、 go camping depends on the weather.二、引导表语从句常用whether(1).The question is whether he can finish the work by the end of this week 问题是到这周末他是否能完成这个工作。(2).What we want to know is whether he will come to speak to us 我们想知道的是他能否来给我们讲话。3.The question is whether it is worth doing.三、引导同位语从句，常用whether.(1).The qu

3、estion whether he will come is important他是否来这个问题很重要。(2).The plan whether well go outing tomorrow hasnt been made明天我们是否郊游这个计划还没订。(3).The question whether we need it has not been decided.四、引导宾语从句。引导及物动词的宾语从句，用whether, if皆可；介词的宾语从句，一般只用whether引导；在whetheror not结构中，口语用if也可以，但whether or not，不可换用if；宾语从句放句首

4、只能用whether引导。whether 和if常与or not 连用，但whether 和or not既可以合起来使用，也可以分开使用。if和or not只能分开使用。宾语从句放句首只能用whether引导。(1).He asked whether/if they would come or not.(2).I want to know whether/if he lives there我想知道他是否住在那儿。(3).I worry about whether I hurt her feeling我担心是否伤了她的感情。(4).I asked him whether/if he would

5、come or not，或I asked whether or not he would come我问他来还是不来。(5)Whether it is true，I cant say这件事是否真实，我不能说。五、与不定式构成起名词作用的短语，用作主语，表语，宾语时，只用whether，不用if. 例如：I dont know whether to see her我不知道是不是去看她。六、当if引导从句，有可能与条件状语相混而产生此义时，要用whether例如：Let me know if you can come释义有：第一，把know看作不及物动词，由if引导条件状语从句，意为“如果你能来，请

6、通知我”；第二，把know当作及物动词，由if引导宾语从句，意为“告诉我你是否能来”。所以，要表达后者意义，必须把if换为whether。Ill tell you whether he is busy. (如果将句中的whether改成if,则又歧义，因为if 还有“如果”之意)学以致用：选择if或whether或两者皆可，完成下面的句子1I have no idea we shall have a meeting2He hasnt asked me I have time to go with you3 he has gone to Shanghai is not known yet4I a

7、m not interested in youll come5I dont care the train arrives on time or not6.Ask him _ he can come.7.I wonder _ it is right answer.8.She doesnt know _ to go the cinema or watch TV.9.I want to know _ or not he is well.10._ the Olympic Games will be held in Beijing in 2008 has been decided yet.11.-When will the sports meet be held ? - It depends on _ it rains the day after tomorrow.12.We havent settled the question of _ it is necessary for him to study abroad.(06江苏) A. if B. where C. whether D. that 答案：1. whether 2. whether/if 3. Whether