sci vs sei, What's the Difference?

Which to use

“sci” is a noun and “sei” is an intj - they look or sound alike but fill different roles in a sentence.

#29,904
“sci” frequency rank: #118
“sei” frequency rank: 30022
confusion score

Side-by-Side Comparison

Feature	sci	sei
Definition	esqui, placa geralmente de madeira para deslizar na água ou na neve	expressa que aquilo ouvido que foi dito ou afirmado por alguém não é tomado como sendo a verdade

Letter map: sci vs sei

Shared letters muted; letters that set sci and sei apart highlighted. Shared run: 2.

3 ch

sci

3 ch

sei

Role in the sentence - sci and sei

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: sci is anoun and seianintj. On the page they differ by a single letter - c in “sci” becomes e in “sei”. Our composite confusion score for this pair is 30022, derived from the frequency rank of both members and their visual similarity.

sci is recorded at frequency rank #29,904, classified as anoun, pronounced /ˈʃi/. sei is at rank #118, tagged as anintj.

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 30022, this pair ranks #38,449 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of sci vs sei

Shared letters: is. Private to "sci": c. Private to "sei": e.

"sci" · 3 letters · shape CCV · "sei" · 3 letters · shape CVV

Frequently Asked Questions

Is swapping "sci" for "sei" ever safe?

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

In ordinary Portuguese text, does "sci" or "sei" show up more?

"sei" is the more common of the two: it sits at frequency rank #118 in our Portuguese list, against #29,904 for "sci". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

Done with this confusable. These links stay specific to "sci" and "sei".

Full dictionary entry for "sci" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "sei" - compare definitions side by side with the headword page. Word entry
This pair ranks #38,449 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"sci" and "sei" also get mixed up with nearby pairs, the highest-scored neighbour is "Sau vs sci". Nearby pair

Confusion rank #38,449 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.