can vs can't, What's the Difference?

Which to use

“can” is a noun and “can't” is a contraction - they look or sound alike but fill different roles in a sentence.

#4,535
“can” frequency rank: #8,727
“can't” frequency rank: 13262
confusion score

Side-by-Side Comparison

Feature	can	can't
Definition	cão	contração de can not; cannot

Where the spellings diverge

Shared letters are muted; the letters that actually set can and can't apart are highlighted. They share 3 letters in sequence, which is exactly why the eye skips the difference.

3 ch

can

5 ch

can't

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: can is /kaŋ/ while can't is cant, Kant. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “can” sits inside “can't”, and the parts of speech differ too (noun vs contraction), which is usually the fastest check. Our composite confusion score for this pair is 13262, derived from the frequency rank of both members and their visual similarity.

can is recorded at frequency rank #4,535, classified as anoun, pronounced /kaŋ/. can't is at rank #8,727, tagged as acontraction, pronounced cant, Kant.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 13262, this pair ranks #59,148 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of can vs can't

Shared letters: acn. Private to "can": -. Private to "can't": t.

"can" · 3 letters · shape CVC · "can't" · 4 letters · shape CVCC

Frequency comparison

can#4,535

can't#8,727

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "can" and "can't" be used interchangeably?

No - they are not even the same part of speech. "can" is a noun and "can't" a contraction, so a sentence built for one is usually ungrammatical with the other.

Which is more common, "can" or "can't"?

"can" is the more common of the two: it sits at frequency rank #4,535 in our Portuguese list, against #8,727 for "can't". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Remembering can vs can't

The fastest way to pick the right one every time.

Check the role first: if you need a noun, it's “can”; for a contraction, it's “can't”.
See each word in full, definition, IPA, etymology and its other confusables. Full “can” entry
Browse more pairs most likely to be confused. Most confusable