aux vs eau, What's the Difference?

Which to use

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

#32,511
“aux” frequency rank: #24,842
“eau” frequency rank: 57353
confusion score

Side-by-Side Comparison

Feature	aux	eau
Definition	Contracción de la preposición à y el artículo les; a las ; a los.	Agua.

Same sound, different letters: aux vs eau

Muted letters are shared; highlighted letters are the only spelling cue when pronunciation matches. Shared run: 2 letters.

3 ch

aux

3 ch

eau

Same sound, different spelling - aux / eau

Say them out loud and nothing separates them: aux and eau carry the same recorded pronunciation, /o/. Grammar is what tells them apart: one is acontraction, the other anoun, so most sentences will only accept one of them. They share most of their letters but differ in 3 positions. Our composite confusion score for this pair is 57353, derived from the frequency rank of both members and their visual similarity.

aux is recorded at frequency rank #32,511, classified as acontraction, pronounced /o/. eau is at rank #24,842, tagged as anoun, pronounced [o].

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 57353, this pair ranks #70,827 of 323,831 scored Spanish confusable pairs - among the most confusable pairs.

Orthographic DNA of aux vs eau

Shared letters: au. Private to "aux": x. Private to "eau": e.

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

Frequently Asked Questions

Can "aux" and "eau" be used interchangeably?

No - they are not even the same part of speech. "aux" is a contraction and "eau" a noun, so a sentence built for one is usually ungrammatical with the other.

In ordinary Spanish text, does "aux" or "eau" show up more?

"eau" is the more common of the two: it sits at frequency rank #24,842 in our Spanish list, against #32,511 for "aux". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

"aux" and "eau" share a sound, keep the gloss open, then jump to the headword or a nearby trap.

Full dictionary entry for "aux" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "eau" - compare definitions side by side with the headword page. Word entry
This pair ranks #70,827 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
"aux" and "eau" also get mixed up with nearby pairs, the highest-scored neighbour is "atl vs aux". Nearby pair

Confusion rank #70,827 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.