以下是引用lookatjoey在2006-9-14 1:03:00的发言：谢了 1. indirect quesitons
We can generally use both whether and if to introduce indirect yes/no questions.
I'm not sure whether/if I'll have time.
I asked whether/if she had any letters for me.
After some verbs, whether is preferred to if.
We discussed whether we should close the shop.
In a formal style, whether is usually preferred in a two - part question with or.
Let me know whether you can come or not. (....if you can come or not is also possible.)
The directors have not decided whether they will recommend a dividend or reinvest the profits.
If an indirect question is fronted, whether is used.
Whether I'll have time I'm not sure at the moment.
2. prepositions
After prepositions, only whether is possible.
There was a big argument about whether we should move to a new house. (NOT....about if we should move...)
I haven't settled the quesiton of whether I'll go back home. (NOT....quesiton of if...)
3. infinitives
Whether, but not if, is used before to - infinitives.
THey can't decide whether to get married now or wait. (NOT they can't decide if to get married...)
4. subject, complement and adverbial clauses
When a question-word clause is a subject or complement, whether is normally preferred.
Whether we can stay with my mother is another matter. (subject)
The quesiton is whether the man can be trusted. (complement)
If is sometimes possible in a very informal style.
The quesion is if the man can be trusted.
Whether you like it or not, I'm staying here.
HTH (Hope that helps)
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发表于 2006-9-14 01:03:00
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