Word Choice – If Versus Whether

Pam’s question: “Please do a future issue on ‘if’ versus ‘whether.’  When asked to review documents, I often see my associates using ‘if’’ incorrectly. I would like to be able to give them a simple explanation.”

BizWritingTip response: There are several rules regarding “if” and “whether.” I have tried to simplify them as much as possible. The first rule is the easiest.

1.   If you are expressing a simple condition, use “if.” (This is a good example.)
If you can’t attend, please let us know.  (Contact us only if you can’t attend.)
If you are going to attend, do you want to carpool? (We won’t expect to carpool, if you are not going.)

2.   Use “whether” if there are two alternatives – even if the alternative is only implied.
Please let us know whether you can attend. (You should let us know your plans either way.)
Let’s discuss whether this is the right thing to do – or not.

3.   Use “whether” after the infinitive form of a verb. (These are the verbs beginning with “to.”)
I am trying to decide whether I should work overtime.
I need to know whether we can hire a part-time person for the summer.

4.   “Whether” and “if” are interchangeable if the answer would be yes or no.
Examples (correct)
She tried to remember whether she had replied to his email. (Yes, she did.)
She tried to remember if she had replied to his email. (Yes, she did.)

5.   “Whether” and “if” are interchangeable in whether/or or if/or constructions.
I would like to know if the figures are accurate or they are estimates.
I would like to know whether the figures are accurate or they are estimates.

Note: “Whether” is considered the more formal word. If you are writing a report or a formal letter and have the option of using “whether” or “if” (rules 4 and 5), I would use “whether.” If you are writing an email or an informal letter and have the option, then use “if.”