Hi, there. I'm happy to give my 2 cents here.

First of all, the big train-wreck grammar mistake in these situations would be to use "if" instead of "whether". That's the BIG rule, and you already seem clear on that.

Sentences #2 & #3 are grammatically suspect --- not outright wrong, but technically they are redundant. If I say --- "I am not sure whether I would be going to office" --- that already implies a choice, an uncertainty --- it already implies that I may or may not go to the office. Therefore, adding the words "or not" don't really add any new meaning to the sentence --- they are redundant. I am not sure I have ever seen GMAT SC get so picayune as to test on that subtlety, but it's good to keep in mind.

The first sentence is an interesting, and rare, case --- presenting a second alternative that is not merely "not" + the first alternative.

I am not sure whether I would be going to office or would be taking a leave.

This is perfectly correct.

Incidentally, I want to caution you -- all three of these have involve the subjunctive, which only would be appropriate if this sentence were part of some hypothetical scenario.

In other words, if the primary decision is simply about going to work, a decision wholly self-contained and not dependent on any other uncertain/unknown external factor, then I would say:

I am not sure whether I am going to work right now. . . . or . .

I am not sure whether I will go to work tomorrow

The subjunctive would be appropriate only there is some larger uncertain/unknown external factor at play. That could be --- my wife goes into labor, a 9.0 earthquake strikes, the power goes out, the Apocalypse commences, or the Cubs win the World Series --- if any one of those were to happen tomorrow, then I am not sure whether I would go to work.

Also, we wouldn't have to use the present progressive "would be going", unless we needed to emphasize that something else were simultaneous with my action of going to work.

Does all that make sense? Let me know if you have any questions at all about this.

Mike

Dear Kavithashravani,

That's a great question.

The structure "whether or not" is not technically incorrect, but it is frowned upon. The reason is: it's redundant. Consider the following sentence.

I do not know whether it will rain later today.

This first sentence already conveys perfectly clearly the uncertainty in my knowledge --- later in the day, it may rain, it may not rain, and I don't know which will occur. Now, consider the sentence:

I do not know whether or not it will rain later today.

This second sentence means exactly the same thing. No new information has been added. We have added extra words that don't change the meaning of the sentence in the least.

Now, as you may remember, in addition to testing grammar, GMAT SC also tests concision and clarity: is the sentence said briefly, elegantly, with no ambiguity? Grammatical, terse, and clear --- that's the GMAT ideal. Given that, adding extra words that don't change the meaning is precisely what the GMAT wants you to avoid on SC.

Does that make sense?

Mike

Dear pappueshwar

Yes, that sentence . . .

If i were you, i would have eaten all the grapes.

is a 100% correct example of the use of the subjunctive. Notice that the first part is present subjuctive, and the last part is past subjunctive. That's fine --- just be aware that we can have different tenses with the subjunctive.

This is all a little off topic in this particular post, because this thread is about the use of "whether". We can, though, combine this subjunctive idea with a "whether" statement.

If I had come home later than her, I am not sure whether I would have eaten all of the grapes.

That is a perfectly correct use of the subjunctive with the word "whether" and with both clauses in the past tense .

If I were you, I don't know whether I would buy more grapes.

That is a perfectly correct use of the subjunctive with the word "whether" and with both clauses in the present tense.

Does that make sense? Does that answer your question?

Mike