什么时候用 if 不用 whether?

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/05 10:31:41
什么时候用 if 不用 whether?

什么时候用 if 不用 whether?
什么时候用 if 不用 whether?

什么时候用 if 不用 whether?
whether用的范围比if大.

If引导条件状语从句时不能用 whether。

你好!
if 和whether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。
例如:
I wonder if / whether I can get some money from you.
Ask her whether / if she can come.
但是在有些情况下,whether和if的用法有一定区别。
例...

全部展开

你好!
if 和whether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。
例如:
I wonder if / whether I can get some money from you.
Ask her whether / if she can come.
但是在有些情况下,whether和if的用法有一定区别。
例如:
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.

收起