Whether or not, and Grice, "Avoid unnecessary prolixity"

“Determine whether or not the process is in control”

may be better than

“Determine whether the process is in control”.

On the other hand,

“Determine whether the process is in control”

does have an obvious implied (implicated, even entailed) second alternative.

Here's what my dictionary of choice (WordWeb (http://www.wordweb.info)) has to say about whether:

Conjunction: whether
1. Introduces two alternatives
"it will take ages whether you drive or fly"

"whether or not" will make most serious grammarians cringe.

Since "whether" indicates two alternatives, the "or not" is egregiously redundant.


"Determine whther the process is under control."

No "...or not...";

No "...if...";

No "...in control..." (unless the process is, in fact, controlling something).

Whether, dammit.


Is it more acceptable if the "or not" is moved to the end?

As in

"Determine whether the process is under control or not."

Personally, I've heard the "whether or not" construction so many times in formal and informal settings that I assumed it was OK. Maybe it's idiomatic.

One pointless nitpick:

"Determine whether the process is under control."

probably shouldn't have the capital D and a full stop because it's not a complete sentence - unless it's an imperative command.

"Hey! You over there! Yeah, I'm talking to you! Determine whether the process is under control! NOW!"

Regardless of placement, the "or not" is redundant.

"Whether" includes (or, strictly, entails) the "or not", just like "descending down the stairs," where descending includes "down."

Yes, it's commonly used, and yes, it's grammatically repetitive.

I'd like to add that the only time "or not" is correct is when either of two situations applies:

"We're going on the picnic whether it rains or not."

"Whether the allegations are true or not, they have seriously injured the senator's reputation."

And so on.