se vs su, What's the Difference?

Which to use

“se” is a conjunction and “su” is an adjective - they look or sound alike but fill different roles in a sentence.

#16
“se” frequency rank: #6,713
“su” frequency rank: 6729
confusion score

Side-by-Side Comparison

Feature	se	su
Definition	indica hipótese	dele

Letter map: se vs su

Shared letters muted; letters that set se and su apart highlighted. Shared run: 1.

2 ch

Part-of-speech tell for se / su

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: se is aconjunction and suanadjective. On the page they differ by a single letter - e in “se” becomes u in “su”. Our composite confusion score for this pair is 6729, derived from the frequency rank of both members and their visual similarity.

se is recorded at frequency rank #16, classified as aconj, pronounced /sɨ/. su is at rank #6,713, tagged as anadj.

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 6729, this pair ranks #67,636 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of se vs su

Shared letters: s. Private to "se": e. Private to "su": u.

"se" · 2 letters · shape CV · "su" · 2 letters · shape CV

Frequently Asked Questions

Can "se" and "su" be used interchangeably?

No - they are not even the same part of speech. "se" is a conjunction and "su" an adjective, so a sentence built for one is usually ungrammatical with the other.

Frequency check: "se" vs "su" - which ranks higher?

"se" is the more common of the two: it sits at frequency rank #16 in our Portuguese list, against #6,713 for "su". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

You've compared "se" and "su". Here's where to go from here.

Full dictionary entry for "se" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "su" - compare definitions side by side with the headword page. Word entry
This pair ranks #67,636 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"se" and "su" also get mixed up with nearby pairs, the highest-scored neighbour is "Sau vs su". Nearby pair

Confusion rank #67,636 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.