sivsskinWhat's the difference?

Quick tell: si is a pronoun, skin is a noun, so they fill different roles in a sentence.

Which to use

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

#482
“si” frequency rank
#18,716
“skin” frequency rank
19198
confusion score

Side-by-Side Comparison

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

Where the eye mixes si and skin

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

2 ch
si
4 ch
skin

Visual trap between si and skin

These two trip readers on the page rather than in the ear: si is /ˈsi/ while skin is /ˈskin/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 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 19198, derived from the frequency rank of both members and their visual similarity.

si is recorded at frequency rank #482, classified as apron, pronounced /ˈsi/. skin is at rank #18,716, tagged as anoun, pronounced /ˈskin/.

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 19198, this pair ranks #51,597 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of si vs skin

Shared letters: is. Private to "si": -. Private to "skin": kn.

"si" · 2 letters · shape CV  ·  "skin" · 4 letters · shape CCVC

Known mistypes of this pair

  • skinksin · sikn · skinn · skkin · skni · sskin

Frequently Asked Questions

Can "si" and "skin" be used interchangeably?
No - they are not even the same part of speech. "si" is a pronoun and "skin" a noun, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "si" vs "skin" - which ranks higher?
"si" is the more common of the two: it sits at frequency rank #482 in our Portuguese list, against #18,716 for "skin". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

Eye-level mix-up between "si" and "skin" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "si" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "skin" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #51,597 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "si" and "skin" also get mixed up with nearby pairs, the highest-scored neighbour is "skin vs slip". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #51,597 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list