ath vs au, What's the Difference?

Which to use

“ath” and “au” are a confusable French pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#31,830
“ath” frequency rank: #24
“au” frequency rank: 31854
confusion score

Side-by-Side Comparison

Feature	ath	au
Definition	Contraction de la préposition a et de l'article défini eth.	Contraction de la préposition à et de l'article défini le.

Where the eye mixes ath and au

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch

ath

2 ch

Look-alike desk: ath vs au

A purely visual mix-up. ath (\at\) and au (\o\) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 31854, derived from the frequency rank of both members and their visual similarity.

ath is recorded at frequency rank #31,830, classified as anarticle, pronounced \at\. 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 31854, this pair ranks #301,126 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of ath vs au

Shared letters: a. Private to "ath": ht. Private to "au": u.

"ath" · 3 letters · shape VCC · "au" · 2 letters · shape VV

Frequently Asked Questions

Is swapping "ath" for "au" ever safe?

No. They are said differently (\at\ versus \o\) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.

In ordinary French text, does "ath" or "au" show up more?

"au" is the more common of the two: it sits at frequency rank #24 in our French list, against #31,830 for "ath". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

Eye-level mix-up between "ath" and "au" is sorted above. Next: full entries or other pairs that share a letter shape.

Full dictionary entry for "ath" 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 #301,126 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
"ath" and "au" also get mixed up with nearby pairs, the highest-scored neighbour is "ath vs aur". Nearby pair

Confusion rank #301,126 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.