For nearly all of my professional writing life, part of my job has included editing others’ work. During that time I’ve learned that most people don’t understand capitalization, subscribe to all manner of superstitions around how sentences should begin and end, and generally use far too many words.
Here’s another thing: People are far more likely to write if when they ought to use whether. Paul Brians explains the difference:
“If” is used frequently in casual speech and writing where some others would prefer “whether”: “I wonder if you would be willing to dress up as a giant turnip for the parade?” Revise to “I wonder whether. . . .” “If” can’t really be called an error, but when you are discussing two alternative possibilities, “whether” sounds more polished. (The two possibilities in this example are: 1) you would be willing or 2) you wouldn’t. In sentences using “whether” “or not” is often understood.) Don’t substitute the very different word “whither,” which means “where.”
The way I was taught is that if is conditional, i.e., if X, then Y.
“If I were a rich man,” sings Tevye in Fiddler on The Roof,
I’d build a big tall house with rooms by the dozen
Right in the middle of the town
A fine tin roof with real wooden floors below
There would be one long staircase just going up
And one even longer coming down
And one more leading nowhere, just for show
See how that works? If he were rich, then he’d blow his money.
But if you’re wondering about the state of Tevye’s finances, you might ask one of his friends, “Do you know whether Tevye is rich?” There are two possibilities, neither of which is conditional: (1) yes, he’s rich, or (2) no, he’s not.
And right about now you’re thinking to yourself, I wonder whether Aaron is this much of a pedant in real life.