sec vs su, What's the Difference?

Which to use

“sec” and “su” are a confusable Spanish pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#17,813
“sec” frequency rank: #20
“su” frequency rank: 17833
confusion score

Side-by-Side Comparison

Feature	sec	su
Definition	Seco	Adjetivo posesivo de la tercera persona; de él, de ella, de ellos, de ellas.

Where the eye mixes sec and su

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

3 ch

sec

2 ch

Visual trap between sec and su

A purely visual mix-up. sec ([sɛk]) and su ([su]) 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 letter(s) in length. Our composite confusion score for this pair is 17833, derived from the frequency rank of both members and their visual similarity.

sec is recorded at frequency rank #17,813, classified as anadj, pronounced [sɛk]. su is at rank #20, tagged as anadj, pronounced [su].

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 17833, this pair ranks #270,515 of 323,831 scored Spanish confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of sec vs su

Shared letters: s. Private to "sec": ce. Private to "su": u.

"sec" · 3 letters · shape CVC · "su" · 2 letters · shape CV

Frequently Asked Questions

Do "sec" and "su" mean the same thing in a sentence?

No. They are said differently ([sɛk] versus [su]) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.

Which is more common, "sec" or "su"?

"su" is the more common of the two: it sits at frequency rank #20 in our Spanish list, against #17,813 for "sec". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

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

Full dictionary entry for "sec" 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 #270,515 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
"sec" and "su" also get mixed up with nearby pairs, the highest-scored neighbour is "sec vs stem". Nearby pair

Confusion rank #270,515 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.