Could care less vs. Could not care less

Could care less

/kʊd kɛr lɛs/

An expression used to indicate that someone does not care at all about something, often used sarcastically or ironically.

Examples:

He might say he could care less, but he really does.You insist you could care less about the results, don't you?When it comes to dancing, I truly could care less.

Synonyms:

unconcerned

Antonyms:

This word has no antonyms

Could not care less

/kʊd nɒt keə lɛs/

Used to emphasize that one is not at all concerned or interested

Examples:

She could not care less about what others think of her.He could not care less if the concert got canceled.Frankly, I could not care less about their argument.

Synonyms:

indifferentunconcernedapatheticdisinterestednonchalant

Antonyms:

concernedinterestedattentivecuriouseager

Ways to tell them apart:

• Could care less suggests that there is still some level of care, as you haven't reached the bottom of your caring capacity.
• Could not care less indicates that you've reached the minimum level of care possible, and you cannot reduce it any further.
• Remember that not in could not care less intensifies the lack of concern—it's like saying you are at the lowest point of caring.
• In British and American English, could not care less is the grammatically correct form to express complete indifference.
• Could care less is often used incorrectly to mean the same thing as could not care less, but it implies the opposite.