ADP vs au, What's the Difference?

Which to use

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

#17,330
“ADP” frequency rank: #24
“au” frequency rank: 17354
confusion score

Side-by-Side Comparison

Feature	ADP	au
Definition	Sigle de l’adénosine diphosphate, molécule intervenant couramment dans les organismes vivants pour permettre des échanges d’énergie.	Contraction de la préposition à et de l'article défini le.

Where the eye mixes ADP and au

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

3 ch

ADP

2 ch

Why the eye confuses ADP with au

These two trip readers on the page rather than in the ear: ADP is \a de pe\ 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 (noun vs article), which is usually the fastest check. Our composite confusion score for this pair is 17354, derived from the frequency rank of both members and their visual similarity.

ADP is recorded at frequency rank #17,330, classified as anoun, pronounced \a de pe\. 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 17354, this pair ranks #383,597 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of ADP vs au

Shared letters: a. Private to "ADP": dp. Private to "au": u.

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

Frequently Asked Questions

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

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

Which is more common, "ADP" or "au"?

"au" is the more common of the two: it sits at frequency rank #24 in our French list, against #17,330 for "ADP". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

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

Full dictionary entry for "ADP" 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 #383,597 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
"ADP" and "au" also get mixed up with nearby pairs, the highest-scored neighbour is "ADP vs aur". Nearby pair

Confusion rank #383,597 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.