AU vs auld, What's the Difference?

Which to use

“AU” is a noun and “auld” is an adjective - they look or sound alike but fill different roles in a sentence.

#6,867
“AU” frequency rank: #31,071
“auld” frequency rank: 37938
confusion score

Side-by-Side Comparison

Feature	AU	auld
Definition	Initialism of alopecia universalis.	Old.

Letter map: AU vs auld

Shared letters muted; letters that set AU and auld apart highlighted. Shared run: 2.

2 ch

4 ch

auld

Role in the sentence - AU and auld

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: AU is anoun and auldanadjective. On the page they differ by 2 extra letter(s) - “AU” sits inside “auld”. Our composite confusion score for this pair is 37938, derived from the frequency rank of both members and their visual similarity.

AU is recorded at frequency rank #6,867, classified as anoun. auld is at rank #31,071, tagged as anadj, pronounced /oʊld/.

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 37938, this pair ranks #290,225 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of AU vs auld

Shared letters: au. Private to "AU": -. Private to "auld": dl.

"AU" · 2 letters · shape VV · "auld" · 4 letters · shape VVCC

Known mistypes of this pair

auld ← alud · audl · auldd · aulld · uald

Frequently Asked Questions

Do "AU" and "auld" mean the same thing in a sentence?

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

Frequency check: "AU" vs "auld" - which ranks higher?

"AU" is the more common of the two: it sits at frequency rank #6,867 in our English list, against #31,071 for "auld". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Done with this confusable. These links stay specific to "AU" and "auld".

Full dictionary entry for "AU" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "auld" - compare definitions side by side with the headword page. Word entry
This pair ranks #290,225 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"AU" and "auld" also get mixed up with nearby pairs, the highest-scored neighbour is "alc vs auld". Nearby pair
Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #290,225 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.