2026届高考英语二轮复习：名词性从句连接词whether与if的选用 课件(共13张PPT)

(共13张PPT)
名词性从句whether与if的选用
高中英语语法系列
1. My question is whether Polly can find her way home. (M3,P8)
2. Scientists are interested in whether the sense of smell is related to pain.
They are also curious about whether it is the same for both sexes. (M3,P9)
3. She wondered if / whether the buses would be still running. (M3, P10)
4. I want to know whether or not the train goes to King Street.
I want to know if or not the train goes to King Street. (M3, P10)
观察与思考
？？？有时whether与if可以等同，有时只能选其中之一？
它们之间到底有什么相同和不同？
if
whether
口诀：whether与if异同
主从表从同位从，if不用whether用；
偏要if引主从，形式主语来帮忙；
其他情况可换用，避免歧义选whether；
discuss、介词后，whether前来引宾从；后面紧跟不定式、or not，又是whether显神通；
宾从若是否定句，if发挥其功用.
主从表从同位从，if不用whether用
引导主语从句
引导表语从句
引导同位语从句
Whether the meeting will be held is still a question．
The question is whether the meeting will be held．
I have no idea whether the meeting will be held．
________________________________________________
________________________________________________
________________________________________________
偏要if引主从，形式主语来帮忙
Whether the meeting will be held is still a question．
If the meeting will be held is still a question．
If
It is still a question whether / if the meeting will be held．
________________________________________________
_______________
结论：除了使用it做形式主语，if可以引导主语从句，if后引出的一般都是宾语从句，多数可以与whether换用。
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______________________________________
其他情况可换用，避免歧义选whether
Please let me know if you need help.
Please let me know if you need help.
Please let me know whether you need help.
_________________________
_________________________
__________________________________
请告诉我你是否需要帮助。
如果你需要帮助请通知我。
discuss、介词后，whether前来引宾从
The plan depends on whether we have enough money.
We will discuss whether we have enough money to finish the plan.
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_______________________________________________
后面紧跟不定式、or not，又是whether显神通
I don’t know whether to see her．
I asked whether or not he would come．
I asked if or not he would come．
I asked him whether/if he would come or not.
___________________________
_____________________
____________
________________________________________________
宾从若是否定句，if发挥其功用
I don't care if you won't come.
I don't care whether you won't come.
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_________________________
I don't care whether/if you come or not.
I don't care whether or not you come.
小结
当拿到考题，确定“是否”符合题意，无需再想if和whether的诸多区分条目，只需看三点：
1.是不是it做形式主语，引导主语从句
2.是不是及物动词引导的宾语从句，discuss除外
3.宾从若是否定句，只能用if
高考直通车
It is not immediately clear ___________the financial crisis will soon be over. (上海卷)
My consideration is ________ the financial crisis in the USA will heavily influence China. (北京卷)
At first he hated the new job but decided to give himself a few months to see ____________it got any better. (北京卷)
whether/if
whether/if
whether
_____
_____
_____
Thank you!