Which to use
“au” is an article and “auto” is a noun - they look or sound alike but fill different roles in a sentence.
- #24
- “au” frequency rank
- #1,803
- “auto” frequency rank
- 1827
- confusion score
Side-by-Side Comparison
| Feature | au | auto |
|---|---|---|
| Definition | Contraction de la préposition à et de l'article défini le. | Automobile. |
Where the eye mixes au and auto
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Visual trap between au and auto
These two trip readers on the page rather than in the ear: au is \o\ while auto is \o.to\. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “au” sits inside “auto”, and the parts of speech differ too (article vs noun), which is usually the fastest check. Our composite confusion score for this pair is 1827, derived from the frequency rank of both members and their visual similarity.
au is recorded at frequency rank #24, classified as anarticle, pronounced \o\. auto is at rank #1,803, tagged as anoun, pronounced \o.to\.
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 1827, this pair ranks #437,315 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of au vs auto
Shared letters: au. Private to "au": -. Private to "auto": ot.
"au" · 2 letters · shape VV · "auto" · 4 letters · shape VVCV
Known mistypes of this pair
- auto ← atuo · auot · autto · uato
Frequently Asked Questions
Do "au" and "auto" mean the same thing in a sentence?
Which is more common, "au" or "auto"?
Useful next steps
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "au" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "auto" - compare definitions side by side with the headword page. Word entry
- This pair ranks #437,315 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "au" and "auto" 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 #437,315 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.