If course, I’m being partly sarcastic and partly ironic when I write that. Since words matter, language purists often point out the phrase ‘I could care less’ is illogical and even an “an ignorant debasement of language“. If you don’t care about something at all, then you cannot care less than you already do. The grammatically proper phrase is “I couldn’t care less”.
Check out UK comedian David Mitchell’s amusing rant on the topic:
Ben Zimmer, language columnist for The Wall Street Journal, writes that ‘could care less’ has become increasingly common in American speech over the last few decades. In fact, it’s estimated ‘could care less’ is used about five times more frequently than ‘couldn’t care less’.
While I’m not a fan of bad grammar, this construct isn’t unique. I can think of two other phrases which mean the same thing both with and without the word ‘not’ in them:
You know diddlysquat. You don’t know diddlysquat.
I can hardly wait. I can’t hardly wait.
Some language etymologists suggest these phrases emerged in the U.S. during the 1950’s to express sarcasm in the style of Yiddish humor. They point to other phrases like ‘I should be so lucky!’ which really means ‘I have no hope of being so lucky’ and ‘Tell me about it!’ which means ‘Don’t tell me about it, because I know all about it already’. My issue with this explanation is most people aren’t being sarcastic when they use the phrase ‘I could care less’.
To me, the most plausible explanation comes from the linguist John Lawler who suggests the phrase ‘could care less’ lost the word ‘not’ through a process he calls negation by association. The most well-known example of this process happened in French. The phrase ‘je ne sais pas’ (which means ‘I do not know’ in English) evolved into the current colloquial phrase ‘je sais pas’. Even though the ‘ne’ (‘not’) is no longer there, the phrase didn’t change its meaning.
Is this really how it happened? I know not but I couldn’t care less.