Whether的用法 I do not know whether I will go. 正确。 I do no know whether or not I will go. Suspect I do not know if I will go. 错误(Manhattan解释为:IF requires a consequence)
Use if for a conditional idea, whether for an alternative or possibility. Thus, Let me know if you'll be coming means that I want to hear from you only if you're coming. But Let me know whether you'll be coming means that I want to hear from you about your plans one way or the other" (Garner, The Oxford Dictionary of American Usage and Style).
whether or not貌似有时候也是正确的,og verbal分册逻辑第10题 At a recent conference on environmental threats to the North Sea, most participating countries favored uniform controls on the quality of effluents, whether or not specific environmental damage could be attributed to a particular source of effluent.
prep 08笔记是这么解释的 1) 在引导宾从的时候只能够用whether,而不能加or not,否则累赘 2) 在引导状从的时候必须加上or not,即whether or not.
摘自Manhattan:
Whether/If
Whether is used when there are alternative choices.
Correct: I don’t know whether I will take the GMAT this month (or not).
Incorrect: Her client didn't tell her if he had sent his payment yet.
Correct: Her client didn't tell her whether he had sent his payment yet.
If is used in a conditional sense.
Ex: If you prepare well you will get a good score.