eauvseinWhich spelling fits?

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

Which to use

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

#24,842
“eau” frequency rank
#36,010
“ein” frequency rank
60852
confusion score

Side-by-Side Comparison

Feature eau ein
Definition Agua. Un uno.

Where the eye mixes eau and ein

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

3 ch
eau
3 ch
ein

Look-alike desk: eau vs ein

These two trip readers on the page rather than in the ear: eau is [o] while ein is [aɪ̯n]. 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 60852, derived from the frequency rank of both members and their visual similarity.

eau is recorded at frequency rank #24,842, classified as anoun, pronounced [o]. ein is at rank #36,010, tagged as anum, pronounced [aɪ̯n].

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 60852, this pair ranks #57,473 of 323,831 scored Spanish confusable pairs - among the most confusable pairs.

Orthographic DNA of eau vs ein

Shared letters: e. Private to "eau": au. Private to "ein": in.

"eau" · 3 letters · shape VVV  ·  "ein" · 3 letters · shape VVC

Frequently Asked Questions

Can "eau" and "ein" be used interchangeably?
No - they are not even the same part of speech. "eau" is a noun and "ein" a num, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "eau" vs "ein" - which ranks higher?
"eau" is the more common of the two: it sits at frequency rank #24,842 in our Spanish list, against #36,010 for "ein". 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 "eau" and "ein" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "eau" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "ein" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #57,473 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "eau" and "ein" also get mixed up with nearby pairs, the highest-scored neighbour is "ein vs EPL". Nearby pair

Confusion rank #57,473 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