si vs sup, What's the Difference?

Which to use

“si” is a pronoun and “sup” is a noun - they look or sound alike but fill different roles in a sentence.

#482
“si” frequency rank: #25,150
“sup” frequency rank: 25632
confusion score

Side-by-Side Comparison

Feature	si	sup
Definition	refere-se à terceira pessoa, indica reflexividade e é usado após preposição (a, de, em, contra, sobre, por, etc., exceto com)	abutre

Where the eye mixes si and sup

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

2 ch

3 ch

sup

Visual trap between si and sup

These two trip readers on the page rather than in the ear: si is /ˈsi/ while sup is /sʊp/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (pronoun vs noun), which is usually the fastest check. Our composite confusion score for this pair is 25632, derived from the frequency rank of both members and their visual similarity.

si is recorded at frequency rank #482, classified as apron, pronounced /ˈsi/. sup is at rank #25,150, tagged as anoun, pronounced /sʊp/.

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 25632, this pair ranks #43,656 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of si vs sup

Shared letters: s. Private to "si": i. Private to "sup": pu.

"si" · 2 letters · shape CV · "sup" · 3 letters · shape CVC

Frequently Asked Questions

Is swapping "si" for "sup" ever safe?

No - they are not even the same part of speech. "si" is a pronoun and "sup" a noun, so a sentence built for one is usually ungrammatical with the other.

Frequency check: "si" vs "sup" - which ranks higher?

"si" is the more common of the two: it sits at frequency rank #482 in our Portuguese list, against #25,150 for "sup". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

Full dictionary entry for "si" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "sup" - compare definitions side by side with the headword page. Word entry
This pair ranks #43,656 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"si" and "sup" also get mixed up with nearby pairs, the highest-scored neighbour is "soap vs sup". Nearby pair

Confusion rank #43,656 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.