sovsstoTell them apart

Quick tell: so is a adverb, sto is a num, so they fill different roles in a sentence.

Which to use

“so” is an adverb and “sto” is a num - they look or sound alike but fill different roles in a sentence.

#3,151
“so” frequency rank
#36,304
“sto” frequency rank
39455
confusion score

Side-by-Side Comparison

Feature so sto
Definition Intensifica las cualidades, normalmente negativas, del sustantivo o adjetivo al que modifica. Ciento.

Where the eye mixes so and sto

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

2 ch
so
3 ch
sto

Why the eye confuses so with sto

These two trip readers on the page rather than in the ear: so is [so] while sto is [ˈsto]. 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 (adverb vs num), which is usually the fastest check. Our composite confusion score for this pair is 39455, derived from the frequency rank of both members and their visual similarity.

so is recorded at frequency rank #3,151, classified as anadv, pronounced [so]. sto is at rank #36,304, tagged as anum, pronounced [ˈsto].

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 39455, this pair ranks #164,388 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of so vs sto

Shared letters: os. Private to "so": -. Private to "sto": t.

"so" · 2 letters · shape CV  ·  "sto" · 3 letters · shape CCV

Frequently Asked Questions

Do "so" and "sto" mean the same thing in a sentence?
No - they are not even the same part of speech. "so" is an adverb and "sto" a num, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "so" vs "sto" - which ranks higher?
"so" is the more common of the two: it sits at frequency rank #3,151 in our Spanish list, against #36,304 for "sto". 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 "so" and "sto" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "so" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "sto" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #164,388 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "so" and "sto" also get mixed up with nearby pairs, the highest-scored neighbour is "stem vs sto". Nearby pair

Confusion rank #164,388 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list