decide + whether or if?

[infinikyte]

In a sentence like ".....decide whether...", in what conditions can "whether" be replaced by "if"? I came across some vigorous debates on this instance particularly pertaining to GMAT.

e.g.
I can't decide whether to live or die. ("if" not applicable here)

And some other examples I can't think of right now... 8)[/i]

[Tdol]

'Whether' is much more common before an infinitive.

[RonBee]

Often you can use either one, but they are not interchangeable.

whether:

• I can't decide whether to live or die.

if:

• I can't decide if I want to live or if I want to die.