Which to use
“auto” is a noun and “aux” is an article - they look or sound alike but fill different roles in a sentence.
- #1,803
- “auto” frequency rank
- #58
- “aux” frequency rank
- 1861
- confusion score
Side-by-Side Comparison
| Feature | auto | aux |
|---|---|---|
| Definition | Automobile. | Contraction obligatoire de la préposition à et de l'article défini les. |
Where the eye mixes auto and aux
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Visual trap between auto and aux
These two trip readers on the page rather than in the ear: auto is \o.to\ while aux is \o\. 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 (noun vs article), which is usually the fastest check. Our composite confusion score for this pair is 1861, derived from the frequency rank of both members and their visual similarity.
auto is recorded at frequency rank #1,803, classified as anoun, pronounced \o.to\. aux is at rank #58, tagged as anarticle, 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 1861, this pair ranks #437,240 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of auto vs aux
Shared letters: au. Private to "auto": ot. Private to "aux": x.
"auto" · 4 letters · shape VVCV · "aux" · 3 letters · shape VVC
Known mistypes of this pair
- auto ← atuo · auot · autto · uato
Frequently Asked Questions
Can "auto" and "aux" be used interchangeably?
Frequency check: "auto" vs "aux" - which ranks higher?
What to do next
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "auto" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "aux" - compare definitions side by side with the headword page. Word entry
- This pair ranks #437,240 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "auto" and "aux" also get mixed up with nearby pairs, the highest-scored neighbour is "aur vs auto". Nearby pair
- Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes
Confusion rank #437,240 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.