non vs Not, What's the Difference?

Which to use

“non” is an adverb and “Not” is a noun - they look or sound alike but fill different roles in a sentence.

#6,793
“non” frequency rank: #3,924
“Not” frequency rank: 10717
confusion score

Side-by-Side Comparison

Feature	non	Not
Definition	não	necessidade

Letter map: non vs Not

Shared letters muted; letters that set non and Not apart highlighted. Shared run: 2.

3 ch

non

3 ch

Not

Grammar separator: non vs Not

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: non is anadverb and Notanoun. On the page they differ by a single letter - n in “non” becomes t in “Not”. Our composite confusion score for this pair is 10717, derived from the frequency rank of both members and their visual similarity.

non is recorded at frequency rank #6,793, classified as anadv. Not is at rank #3,924, tagged as anoun, pronounced /noːt/.

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 10717, this pair ranks #62,306 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of non vs Not

Shared letters: no. Private to "non": -. Private to "Not": t.

"non" · 3 letters · shape CVC · "Not" · 3 letters · shape CVC

Frequently Asked Questions

Is swapping "non" for "Not" ever safe?

No - they are not even the same part of speech. "non" is an adverb and "Not" a noun, so a sentence built for one is usually ungrammatical with the other.

In ordinary Portuguese text, does "non" or "Not" show up more?

"Not" is the more common of the two: it sits at frequency rank #3,924 in our Portuguese list, against #6,793 for "non". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Pair "non" vs "Not" is on the table, pick a follow-up below.

Full dictionary entry for "non" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "Not" - compare definitions side by side with the headword page. Word entry
This pair ranks #62,306 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"non" and "Not" also get mixed up with nearby pairs, the highest-scored neighbour is "non vs noon". Nearby pair

Confusion rank #62,306 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.