si vs sie, What's the Difference?

Which to use

“si” and “sie” are a confusable Portuguese pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#482
“si” frequency rank: #40,788
“sie” frequency rank: 41270
confusion score

Side-by-Side Comparison

Feature	si	sie
Definition	refere-se à terceira pessoa, indica reflexividade e é usado após preposição (a, de, em, contra, sobre, por, etc., exceto com)	ela, pronome pessoal feminino do caso nominativo da terceira pessoa do singular:

Where the eye mixes si and sie

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

2 ch

3 ch

sie

Why the eye confuses si with sie

A purely visual mix-up. si (/ˈsi/) and sie (/zi:/ ouvir^(fonte ?) ouvir^(fonte ?)) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 1 extra letter(s) - “si” sits inside “sie”. Our composite confusion score for this pair is 41270, derived from the frequency rank of both members and their visual similarity.

si is recorded at frequency rank #482, classified as apron, pronounced /ˈsi/. sie is at rank #40,788, tagged as apron, pronounced /zi:/ ouvir^(fonte ?) ouvir^(fonte ?).

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 41270, this pair ranks #24,678 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of si vs sie

Shared letters: is. Private to "si": -. Private to "sie": e.

"si" · 2 letters · shape CV · "sie" · 3 letters · shape CVV

Frequently Asked Questions

Can "si" and "sie" be used interchangeably?

No. They are said differently (/ˈsi/ versus /zi:/ ouvir^(fonte ?) ouvir^(fonte ?)) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.

Which is more common, "si" or "sie"?

"si" is the more common of the two: it sits at frequency rank #482 in our Portuguese list, against #40,788 for "sie". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

Full dictionary entry for "si" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "sie" - compare definitions side by side with the headword page. Word entry
This pair ranks #24,678 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"si" and "sie" also get mixed up with nearby pairs, the highest-scored neighbour is "Sau vs sie". Nearby pair

Confusion rank #24,678 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.