can't
- 1Cannot; used before a verb to say that someone is unable or lacks the ability to do something.
No matter what I try, I can't get the old printer to connect.
She can't read music, but she plays the piano beautifully by ear.
Oppositecan
Note
The contraction of can and not has been in use since 1706 or earlier. Two habits of speech are worth knowing: it closes an impatient tag question, as in shut up, can't you?, and in brisk talk the subject can drop away altogether: can't do that, Shepard, as Mordin answers in Mass Effect 3 (2012).
- 2Used to say that someone is forbidden or not permitted to do something.
Visitors can't park in the staff lot without a permit.
Mom says I can't go to the party unless my homework is done.
Note
Rules and refusals use it: you can't enter without a ticket states a prohibition, not a physical limit. The same words can carry plain inability, so she can't drive may mean she never learned or that she is not allowed, and only context settles which.
- 3Used, often before be, to say that something is logically impossible.
The total can't be right, since the parts add up to less than half of it.
If the alarm was set at midnight, the thief can't have entered after that without tripping it.
Note
Deduction is its business: the butler can't be the murderer because he was in London rules someone out on the facts, and be usually follows. Its opposite here is must, not can (the butler must be the murderer) and for the past it takes have: the thief can't have entered after midnight.
Use it in a sentence
Write your own sentence with can't, and AI will tell you whether it fits and which meaning you used.
Origin
Formed from can + -n't, and in use since 1706 or earlier.