difference between 'if' and 'whether'

[Thang77]

Let's take a look at this exercise:

'''He didn't know..........or go home'''
A. if to wait
B. Whether to wait
C. If that he should wait

First I think the answer is C because if A is correct,B is correct.On the second thoughts, I chooseB. In my opinion,the uses of 'if' and 'whether' are not similar in this case. For example, we say''he is as tall as her'', not say''he is so tall as her'' but''he isn't so/as tall as her''. What about your choice? Please tell me the reasons. Thanks in advance!

[Yankee]

Hi Thang

Only B works in your sentence: whether to wait

'Whether' is used before infinitives (and is usually preferable in sentences with 'or').

I've posted the following link here before. I think the write-up about if vs whether is pretty thorough and also accurate:
http://gmat-grammar.blogspot.com/2006/07/whether-vs-if.html
.

[Duc]

Hello,
I think through email I have given you this link gmat-grammar.blogspot.com/2006/07/whether-vs-if.html already.
Don't you remember ?
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