关于if从句求解Whatdidthewomanaskjustnow?SheaskedwhetherIcouldhelphertofindthepostoffice可是我就疑惑了,这里whether不是相当于if吗?if接从句表是否不是要加will吗?那这里不应该是Iwouldhelp

Question

关于if从句求解
What did the woman ask just now?
She asked __________
whether I could help her to find the post office
可是我就疑惑了,这里whether不是相当于if吗?if接从句表是否不是要加will吗?那这里不应该是I would help才对啊?
我承认我有点白痴，绕了。我混在了这个句式里
I don't know if he will come.If he comes,I'll tell you.
我记得很清楚，就是表是否的时候一定要用will.麻烦各位给我说说，有什么别的情况，怎么记忆，
= =v1.2
那个回答的同学,我是混在了I don't know if he will come.这里不也是是否的意思咩？

Answer 1

这里两个可互换,没有说If要用法will啊
whether和if的用法区别
whether与if作“是否”讲,在用法上有相同之处,也有不同之处.
一、相同之处.
1.whether和if都能引导宾语从句,常置于see,ask,learn,tell,wonder,doubt,find out等动词之后.
如：He asked me whether/is I could help him.I want to know whether/if he lives there.
2.whether和if都可用it作形式主语从句中.如：it's uncertain whether/if he'll come this evening.
3.在be uncertain/doubtful之后,常用whether引导宾语从句,有时也可以用if,如：We are uncertain whether/if Mary will come.
二、不同之处.
1.whether可置于句首引导主语从句,而if不能.如：___the 2000 Olympic Games will be in Beijing is not known yet.A.whether B.If C.Whether D.That 答案是C.
2.whether可用在介词之后,引导宾语从句,而If则不能.如：Success depends on whether we make evough effort.
3.whether可引导表语从句,if则不能.如：The puestion is whether it is not worthdoing.
4.在名词之后引导同位语从句时,用whether而不用if.如：The puestion whether the students answered correctly should be decided by the teacher.
5.whether后可接不定式,而if不能.如：Please tell us whether to go or stay here.
6.在有些动词（如discuss）之后,只能用whether,而不用if引导宾语从句.如：We discussed whether we should close the shop.
7.在引导否定概念in宾语从句时,只能用if,而不用whether.如：he asked me if I hadn't finished my work.
这句有意思
用if会引起歧义时,只用whether.如：
例12 Could you tell me if you know the answer
这句话有两种意思：“你能告诉我是否知道答案吗?”或“如果你知道答案,请告诉我,好吗?”.如用whether可避免歧义.
原来你把这个弄错了
是这样的,If he comes,I'll tell you.是主将从现,就是条件句用一般现在时,主句用一般将来时.这是一种固定句式.If是如果的意思,而She asked 这句if表示是否,意思都不同,表示是否和whether的区别见上
知道了,I don't know if he will come,这里是是否的意思,但是注意,主句用的是一般现在时,意思又是他是否将会来,当然用will了,但是并不是will就一定要用will,还要根据句子意思才能定后面用什么时态.而且这个句子里if也可用whether代替