By Clipper Ledgard
When we are presented with the split “if” or “whether”, we should use “whether” unless it introduces a conditional clause:
I will not run if I am tired. Conditional => Correct
I do not know if I can believe you. Not conditional => Incorrect
If the clause is not a conditional, “whether” must be used:
I do not know whether I can believe you. Not conditional => Correct
I do not know whether or not I can believe you. Not conditional => Correct, but redundant.
I do not know whether I can believe you or not. Not conditional => Correct, but redundant.
I do not know whether to believe you. Not conditional => Correct, concise, best choice.
The expression “whether or not” is not incorrect; it is just redundant and, according to the GMAT, should be avoided. Nevertheless, it is an idiomatic expression, and, as such, we should not discard it right away. In fact, the GMAT itself uses the expression “whether or not” in reading comprehension and critical reasoning questions:
The passage suggests that bank managers failed to consider whether or not the service improvement mentioned in line 19…
Opponents of laws that require automobile drivers and passengers to wear seat belts argue that in a free society people have the right to take risks as long as the people do not harm other as a result of taking the risks. As a result, they conclude that it should be each person’s decision whether or not to wear a seat belt.
Which of the following, if true, most seriously weakens the conclusion drawn above?
It is easy to see that we can eliminate the part “or not” and keep the intended meaning. Nevertheless, we should be aware that in some cases the “or not” part can not be eliminated; when the meaning of the clause is “no matter what…”, the “or not” part is necessary:
I will buy the car whether or not I get the driver’s licence.
The fact that the GMAT has not tested the expression with this meaning does not mean that it will not do so eventually. The GMAT has already used the expression whether or not with this meaning; however, the choices that had the expression whether or not were eliminated for other reasons.
Let’s check the Sentence Correction question 64 from the Verbal Review 2016:
Under high pressure and intense heat, graphite, the most stable form of pure carbon, changes into the substance commonly referred to as diamond and remaining this way whether or not the heat and pressure are removed.
- remaining this way whether or not
- remaining like that even as
- remaining as such whether or not
- remains in this way although
- remains thus even when
Choices 1, 2, and 3 are eliminated because the verb changes is not parallel to the modifier remaining. But we can see in the original sentence that if the “or not” part is omitted in the expression “whether or not”, the sentence will not have the intended meaning.
In short, whether you like it or not, you must think twice before deciding whether to discard “whether or not”.