AEC vs au, What's the Difference?

Which to use

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

#37,154
“AEC” frequency rank: #24
“au” frequency rank: 37178
confusion score

Side-by-Side Comparison

Feature	AEC	au
Definition	Avant l’ère commune. Note d’usage : Placé après une année, un siècle ou un millénaire.	Contraction de la préposition à et de l'article défini le.

Where the eye mixes AEC and au

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

3 ch

AEC

2 ch

Visual trap between AEC and au

These two trip readers on the page rather than in the ear: AEC is \a.ø.se\ while au 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 (adjective vs article), which is usually the fastest check. Our composite confusion score for this pair is 37178, derived from the frequency rank of both members and their visual similarity.

AEC is recorded at frequency rank #37,154, classified as anadj, pronounced \a.ø.se\. 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 37178, this pair ranks #264,323 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of AEC vs au

Shared letters: a. Private to "AEC": ce. Private to "au": u.

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

Frequently Asked Questions

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

No - they are not even the same part of speech. "AEC" is an adjective and "au" an article, so a sentence built for one is usually ungrammatical with the other.

Frequency check: "AEC" vs "au" - which ranks higher?

"au" is the more common of the two: it sits at frequency rank #24 in our French list, against #37,154 for "AEC". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

Full dictionary entry for "AEC" 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 #264,323 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
"AEC" and "au" also get mixed up with nearby pairs, the highest-scored neighbour is "AEC vs aves". Nearby pair

Confusion rank #264,323 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.