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if能引导表语从句吗?

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if能引导表语从句吗?
if能引导表语从句吗?
1
whether和if都可以引导宾语从句,表示“是否”,在口语或间接引语中两者可以互换使用.如:
I wonder if / whether I can get some advice from you.
Ask him whether / if he can come.
但在有些情况下,whether和if的用法有一定区别.
1.whether引导的从句常可以与连词or或or not直接连用,而if一般不能.如:
正:Let me know whether you can come or not.
误:Let me know if you can come or not.
2.当宾语从句提到句首时,只能用whether引导,而不能用if.如:
正:Whether it is true or not,I can’t tell.
误:If it is true or not,I can’t tell.
3.whether可以引导带to的不定式,if则不能.如:
正:I don’t know whether to accept or refuse.
误:I don’t know if to accept or refuse.
4.whether及其引导的成分可放于介词之后,作介词的宾语,但if不能.如:
正:I worry about whether I hurt her feelings.
误:I worry about if I hurt her feelings.
5.whether可以引导从句,作主语、表语或同位语,而if不能.如:
正:It was uncertain whether he would come.
误:It was uncertain if he would come.
正:His first question was whether Tom had arrived yet.
误:His first question was if Tom had arrived yet.
正:We must consider the question whether we will take these measures.
误:We must consider the question if we will take these measures.