Q: My wife (not a native English speaker) gets irked when I (native Canadian English speaker) start a question with “Why don’t you.” She finds it rude, a way of saying she isn’t doing something she should be. Am I being rude?
A: No, you’re not being rude. English speakers often use the idiomatic “Why don’t you” to introduce a proposal or a helpful suggestion in the form of a rhetorical question.
It’s not a criticism, but might sound that way to someone who hasn’t heard it from childhood.
The two of us, a married couple, often use it ourselves: “Why don’t you look under the bed or in the closet?” … “Why don’t you pick up the dry-cleaning on your way?”
This device is also used with “I” or “we,” as in “Why don’t I lift that for you?” … “Why don’t we order pizza and watch a movie?” The same suggestions might be made with “Let me” instead of “Why don’t I” and “Let’s” instead of “Why don’t we.”
Again, these are rhetorical questions, not real questions. They’re ways of suggesting or proposing something in an indirect way.
The Cambridge Dictionary defines “Why don’t you” as an idiom that’s “used to make a suggestion.” The dictionary illustrates with “Why don’t you come with us?”
In explaining this usage, the Oxford English Dictionary says the adverb “why” is used “with the negative form of the simple present tense in formulating a positive suggestion, as ‘why don’t I (we, etc.) …?’ ”
We’ve found examples dating from the early 17th century, before the contraction “don’t” became common and the idiom was “why do you not.”
This passage, for instance, is from a moral dialogue published in 1608: “Why do you not now take your plesure & ease, and feast, and be merrie with your friends? This you may do now, nothing hindreth you” (A Warning for Worldlings, by Jeremy Corderoy).
Contracted “don’t” examples of the expression date from the 1660s onward. The earliest we’ve found are from Restoration comedies.
In John Tatham’s Knavery in All Trades, or, The Coffee-House (1664), a wife suggests to her husband, “Why don’t you come to bed?”
And in another 1664 comedy, one lady advises another about a young lord she might seduce: “Why don’t you try Lonzartes?” (Pandora, by Sir William Killigrew).
The usage has been fairly common ever since. The OED’s most recent example is from a British thriller set in the 1930s: “Why don’t I stop by her compartment … and see how she is?” (Richard Doyle’s Havana Special, 1982).
Your wife is correct in thinking that some rhetorical questions beginning with “Why don’t you” are not meant to be kindly or helpful. “Why don’t you get lost?” is another way of saying, “Get lost!” The same is true of “Why don’t you mind your own business?” and “Why don’t you shut up?”
Context is everything!