On the 11th, Mark Liberman returned to the expression could care less on Language Log, thanks to an xkcd cartoon that day, which I reproduce here:
He uses the expression as an implicitly negative idiom, conveying something like couldn’t care less, but a bit more compactly. She peeves at him, he analyzes what she might be doing with her peeve, and eventually he uses the idiom to her.
In a little while, I’ll create a CARE LESS Page on this blog, so I can maintain an updateable inventory of postings on the topic. Notes:
(a) the implicitly negative expression could care less has been attested for about 50 years, and explicitly negative couldn’t care less is only a bit older
(b) the expression is almost entirely American
(c) the expression has been steadily increasing in frequency, at the expense of the explicitly negative variant, though both continue in use
(d) the expression has provoked a firestorm of peeving, over many years, from people who insist that it’s simply a mistake, that it’s “illogical”, that it can’t be understood literally — that is, from people who refuse (despite the evidence of everyday usage) to recognize that it involves an idiom
The linguablog postings have concentrated on the origins of could care less (at some point, that question becomes intellectually intriguing but no longer relevant to usage) and on the way it’s used now, about which there’s more to be said: since many speakers have both variants, there are probably subtle differences in the way the two are used. There is some suggestion, in fact, that could care less is emphatically or strongly negative, as opposed to the flatter, more neutral explicitly negative variant, in which case the man’s use of could care less in the last panel of the xkcd comic is a strong rejection of the woman’s peeving.
But that idea needs to be systematically examined.
