What is the difference between "whether" and "if"?

[Tung Quoc]

Please read:
1. I asked him whether he had done all the work himself or whether he had had any assistance.
2. I asked him whether he had done all the work himself or he had had any assistance.
3. I asked him if he had done all the work himself or if he had had any assistance.
4. I asked him if he had done all the work himself or he had had any assistance.

I think all are correct? Am I right?

Quoc

[Conchita]

Yes, Quoc, but I would repeat the conjunction for each choice:

I asked him whether/if he had done all the work himself or whether/if he had had any assistance.

[Alan]

Hi,

Whether hints at the idea of yes or no. I asked him if he had finished is simply the indirect version of: Have you finished? I asked him whether he had finished is more open and suggests: Have you or haven't you?

Alan
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