seivssolTell them apart

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

Which to use

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

#48,072
“sei” frequency rank
#716
“sol” frequency rank
48788
confusion score

Side-by-Side Comparison

Feature sei sol
Definition Seis. Estrella del sistema planetario en el que se encuentra la Tierra.

Where the eye mixes sei and sol

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

3 ch
sei
3 ch
sol

Visual trap between sei and sol

These two trip readers on the page rather than in the ear: sei is /s̺ej/ while sol is [ˈsol]. 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 (num vs noun), which is usually the fastest check. Our composite confusion score for this pair is 48788, derived from the frequency rank of both members and their visual similarity.

sei is recorded at frequency rank #48,072, classified as anum, pronounced /s̺ej/. sol is at rank #716, tagged as anoun, pronounced [ˈsol].

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 48788, this pair ranks #112,544 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of sei vs sol

Shared letters: s. Private to "sei": ei. Private to "sol": lo.

"sei" · 3 letters · shape CVV  ·  "sol" · 3 letters · shape CVC

Frequently Asked Questions

Is swapping "sei" for "sol" ever safe?
No - they are not even the same part of speech. "sei" is a num and "sol" a noun, so a sentence built for one is usually ungrammatical with the other.
In ordinary Spanish text, does "sei" or "sol" show up more?
"sol" is the more common of the two: it sits at frequency rank #716 in our Spanish list, against #48,072 for "sei". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

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

  • Full dictionary entry for "sei" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "sol" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #112,544 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "sei" and "sol" also get mixed up with nearby pairs, the highest-scored neighbour is "sei vs stem". Nearby pair

Confusion rank #112,544 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