oi vs oni, What's the Difference?

Which to use

“oi” is an intj and “oni” is a pronoun - they look or sound alike but fill different roles in a sentence.

#631
“oi” frequency rank: #49,618
“oni” frequency rank: 50249
confusion score

Side-by-Side Comparison

Feature	oi	oni
Definition	expressa cumprimento que se faz ao encontrar uma pessoa	pronome pessoal do caso nominativo da terceira pessoa do plural de gênero masculino pessoal, eles

Letter map: oi vs oni

Shared letters muted; letters that set oi and oni apart highlighted. Shared run: 2.

2 ch

3 ch

oni

Grammar separator: oi vs oni

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: oi is anintj and oniapronoun. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 50249, derived from the frequency rank of both members and their visual similarity.

oi is recorded at frequency rank #631, classified as anintj. oni is at rank #49,618, tagged as apron.

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 50249, this pair ranks #14,733 of 75,631 scored Portuguese confusable pairs - among the most confusable pairs.

Orthographic DNA of oi vs oni

Shared letters: io. Private to "oi": -. Private to "oni": n.

"oi" · 2 letters · shape VV · "oni" · 3 letters · shape VCV

Frequently Asked Questions

Can "oi" and "oni" be used interchangeably?

No - they are not even the same part of speech. "oi" is an intj and "oni" a pronoun, so a sentence built for one is usually ungrammatical with the other.

In ordinary Portuguese text, does "oi" or "oni" show up more?

"oi" is the more common of the two: it sits at frequency rank #631 in our Portuguese list, against #49,618 for "oni". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Done with this confusable. These links stay specific to "oi" and "oni".

Full dictionary entry for "oi" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "oni" - compare definitions side by side with the headword page. Word entry
This pair ranks #14,733 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"oi" and "oni" also get mixed up with nearby pairs, the highest-scored neighbour is "oni vs ons". Nearby pair

Confusion rank #14,733 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.