Which word, if or whether, is correct in each of these sentences?
- I am not sure if/whether I need management approval for this purchase.
- Let me know if/whether you plan to ride with us, and I will pick you up.
- The lunch will take place under the tent if/whether it rains.
- Rochelle asked if/whether we will offer this promotion again.
- You may not be able to print your document if/whether you move out of range of our Wi-Fi.
We may not agree on the answers. That might be because we interpret a sentence differently. Or we may follow a looser or stricter style when it comes to if/whether choices. I cover style manual differences below these answers:
- Careful writers and editors choose whether in sentences like this one. In the sentence, there are two possibilities: I need management approval or I don't need it. When writing about more than one possibility or alternative, use whether. Hint: If you can add "or not" to the word and it makes sense, you want whether.
- The choice in this sentence depends on meaning. If the writer wants to know either way (you plan to ride with us/you don't plan to ride with us), the clear choice is whether. (Remember the "whether or not" hint.) But if the writer does not want to hear from you unless you plan to ride with us, if is the correct choice. To me, the second part of the sentence suggests that if expresses the writer's intention. After all, I will not pick you up if you don't plan to ride with us.
- The correct answer is if. If the writer wanted to indicate that the lunch will take place under the tent rain or shine, the phrase "rain or shine" or the clause "whether it rains or not" would be clearer.
- Careful writers and editors would use whether in this sentence, which communicates about two possibilities (we will/we won't offer the promotion again).
- The correct word here is if. Using whether would indicate that no matter where you move, you may be out of range of our Wi-Fi.
A few style manuals on my bookshelf offer these opinions:
The Canadian Press Stylebook says if and whether "are interchangeable when they make sense and are not ambiguous." In other words, The Canadian Press Stylebook supports using either word in sentences 1 and 4.
Garner's Modern American Usage distinguishes between the two words, always using whether for alternatives. Garner would use whether in 1 and 4 and would choose carefully between if and whether in number 2.
The Chicago Manual of Style agrees essentially with Garner. Chicago adds, "Avoid substituting if for whether unless your tone is intentionally informal or you are quoting someone." Chicago also emphasizes that "determine whether" and "decide whether" are preferable to the colloquial (informal) "determine if" and "decide if," unless you want a colloquial style.
The Gregg Reference Manual generally agrees with Chicago. Also, it recommends using whether rather than if in these expressions: "see whether," "learn whether," "know whether," and "doubt whether."
Microsoft Manual of Style uses the traditional approach of Garner and Chicago. Microsoft also advises against using when for if in sentences like this one: "The printer might insert stray characters if [not when] the wrong font is selected."
The Associated Press Stylebook does not cover the use of if and whether.
Do you use the careful or the colloquial approach? Occasionally I use the informal if when readers expect me to use whether. I need to consider my audience and make choices that will help them focus on my message, not on my choice between two words.