Which to use
“A3” is a noun and “au” is an article - they look or sound alike but fill different roles in a sentence.
- #20,334
- “A3” frequency rank
- #24
- “au” frequency rank
- 20358
- confusion score
Side-by-Side Comparison
| Feature | A3 | au |
|---|---|---|
| Definition | Format de papier mesurant 420 mm × 297 mm. | Contraction de la préposition à et de l'article défini le. |
Where the eye mixes A3 and au
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Visual trap between A3 and au
These two trip readers on the page rather than in the ear: A3 is \ɑ.tʁwa\ while au is \o\. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - 3 in “A3” becomes u in “au”, and the parts of speech differ too (noun vs article), which is usually the fastest check. Our composite confusion score for this pair is 20358, derived from the frequency rank of both members and their visual similarity.
A3 is recorded at frequency rank #20,334, classified as anoun, pronounced \ɑ.tʁwa\. au is at rank #24, 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 20358, this pair ranks #368,684 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of A3 vs au
Shared letters: a. Private to "A3": -. Private to "au": u.
"A3" · 1 letters · shape V · "au" · 2 letters · shape VV
Frequently Asked Questions
Can "A3" and "au" be used interchangeably?
Frequency check: "A3" vs "au" - which ranks higher?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "A3" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "au" - compare definitions side by side with the headword page. Word entry
- This pair ranks #368,684 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "A3" and "au" also get mixed up with nearby pairs, the highest-scored neighbour is "A3 vs aur". Nearby pair
Confusion rank #368,684 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.