spavsstoWhat's the difference?

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

Which to use

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

#15,233
“spa” frequency rank
#36,304
“sto” frequency rank
51537
confusion score

Side-by-Side Comparison

Feature spa sto
Definition Grafía alternativa de espá. Ciento.

Where the eye mixes spa and sto

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

3 ch
spa
3 ch
sto

Visual trap between spa and sto

These two trip readers on the page rather than in the ear: spa is [esˈpa] while sto is [ˈsto]. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (noun vs num), which is usually the fastest check. Our composite confusion score for this pair is 51537, derived from the frequency rank of both members and their visual similarity.

spa is recorded at frequency rank #15,233, classified as anoun, pronounced [esˈpa]. 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 51537, this pair ranks #97,380 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of spa vs sto

Shared letters: s. Private to "spa": ap. Private to "sto": ot.

"spa" · 3 letters · shape CCV  ·  "sto" · 3 letters · shape CCV

Frequently Asked Questions

Can "spa" and "sto" be used interchangeably?
No - they are not even the same part of speech. "spa" is a noun and "sto" a num, so a sentence built for one is usually ungrammatical with the other.
In ordinary Spanish text, does "spa" or "sto" show up more?
"spa" is the more common of the two: it sits at frequency rank #15,233 in our Spanish list, against #36,304 for "sto". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

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

  • Full dictionary entry for "spa" 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 #97,380 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "spa" and "sto" also get mixed up with nearby pairs, the highest-scored neighbour is "stem vs sto". Nearby pair

Confusion rank #97,380 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