Earlier today my fellow Baltimorean Max Weiss tweeted as @maxthegirl, "Why do people say, 'I could care less' when they mean the opposite? WHY?!?"

I answered that it's just an idiom, no cause to fret, and she answered, "Nope. The idiom is 'couldn't care less.' "


Having been down that road before, I offered a post by Mark Liberman from Language Log in 2004 which calls could care less "a well-accepted colloquial expression in contemporary American English" and establishes a couple of useful points:

Item: The Oxford English Dictionary lists that sense, dating it to 1946. The OED calls it a colloquial usage, but it also labels couldn't care less as colloquial.

Item: Steven Pinker has speculated that could care less emerged as an expression of adolescent sarcasm, though that explanation has been challenged.

Bryan Garner, who dislikes the expression, cites an article in American Speech that theorizes that slurred speech led to "the loss of this alveolar closure." And fairness demands that I point out that Bill Walsh, whom I hold in great esteem, also advises against the idiom in Yes, I Could Care Less.

Even Messrs. Garner and Walsh concede that could care less is firmly established as a colloquial American English idiom. You probably do not want to use it in formal writing or speech, and you're perfectly free to shun it in your own casual conversation. But you can't pretend that it doesn't exist, or complain that it's illogical (grammar ain't algebra), or deny that you understand it when you come across it.

Ms. Weiss responded to the Language Log post with "Yes, and 'impactful' is a word."

Indeed it is, an adjective formed by normal pattern from a noun, with a spelling, a pronunciation, a meaning, an etymology, numerous citations, and an entry in dictionaries. That makes it a word.

Lexicographers are not holding a gun to your head to force you to use it. Many people dislike it—the American Heritage Dictionary notes that impact was scorned in the 1960s for being used both as a noun and a verb, so hostility is no recent phenomenon. And I got into a spot of trouble over it myself one day in the newsroom.

So shun away. And if you choose to disparage people who use could care less and impactful, keep in mind that what is involved is not grammar and usage so much as indulgence in snobbery.