Q: An article in the San Francisco Chronicle about takeout meals says, “now you can dig into the restaurant’s eight-course tasting menu without having to put on a jacket, let alone pants.” Shouldn’t “jacket” and “pants” be flipped?
A: Yes, we’d flip “jacket” and “pants” in that passage from the Chronicle (Feb. 16, 2021): “now you can dig into the restaurant’s eight-course tasting menu without having to put on pants, let alone a jacket.”
The phrase “let alone” is used here to emphasize something by contrasting it with something less likely. If you don’t have to wear pants, you’re less likely to dress up in a jacket.
Lexico, an online dictionary using the resources of Oxford University Press, says the usage indicates “that something is far less likely or suitable than something else already mentioned.” It gives this example: “he was incapable of leading a bowling team, let alone a country.”
Another online dictionary, Longman, says the phrase is “used after a negative statement to say that the next thing you mention is even more unlikely.” It cites this example: “The baby can’t even sit up yet, let alone walk!”
The phrase is usually used as a conjunction in “sentences with a negative construction or negative overtones,” where “its sense is close to ‘much less,’ ” according to Merriam-Webster’s Dictionary of English Usage.
Merriam-Webster cites a November 1914 letter in which Robert Frost says “I don’t feel justified in worrying, let alone complaining.”
You might also think of “let alone” as contrasting something relatively simple with something more difficult: “We can’t afford to rent, let alone buy” … “I wouldn’t trust him to drive a car, let alone pilot a plane” … “the disease can’t be treated, let alone cured.”
All ten standard dictionaries that we regularly consult say “let alone” is generally used negatively, or cite negative examples of the usage.
The earliest example in the Oxford English Dictionary for the phrase “used colloquially with the sense ‘not to mention,’ ” is from the early 19th century:
“I didn’t hide, nor wouldn’t from any man living, let alone any woman.” From Tales of a Fashionable Life (1812), by Maria Edgeworth.
[Note: A 2012 post discusses the occasional use of the variant “leave alone” in British English, though it says “let alone” is the usual usage in both the US and the UK.]