auvsausWhich spelling fits?

Quick tell: au is a article, aus is a preposition, so they fill different roles in a sentence.

Which to use

“au” is an article and “aus” is a preposition - they look or sound alike but fill different roles in a sentence.

#24
“au” frequency rank
#18,401
“aus” frequency rank
18425
confusion score

Side-by-Side Comparison

Feature au aus
Definition Contraction de la préposition à et de l'article défini le. De (désigne la provenance).

Where the eye mixes au and aus

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

2 ch
au
3 ch
aus

Why the eye confuses au with aus

These two trip readers on the page rather than in the ear: au is \o\ while aus is \aʊ̯s\. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 extra letter(s) - “au” sits inside “aus”, and the parts of speech differ too (article vs preposition), which is usually the fastest check. Our composite confusion score for this pair is 18425, derived from the frequency rank of both members and their visual similarity.

au is recorded at frequency rank #24, classified as anarticle, pronounced \o\. aus is at rank #18,401, tagged as aprep, pronounced \aʊ̯s\.

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 18425, this pair ranks #378,392 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of au vs aus

Shared letters: au. Private to "au": -. Private to "aus": s.

"au" · 2 letters · shape VV  ·  "aus" · 3 letters · shape VVC

Frequently Asked Questions

Is swapping "au" for "aus" ever safe?
No - they are not even the same part of speech. "au" is an article and "aus" a preposition, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "au" or "aus"?
"au" is the more common of the two: it sits at frequency rank #24 in our French list, against #18,401 for "aus". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

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 "aus" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #378,392 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "au" and "aus" also get mixed up with nearby pairs, the highest-scored neighbour is "aus vs aves". Nearby pair

Confusion rank #378,392 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list