a'svsAUCWhat's the difference?

Quick tell: a's is a noun, AUC is an adverb, so they fill different roles in a sentence.

Which to use

“a's” is a noun and “AUC” is an adverb - they look or sound alike but fill different roles in a sentence.

#15,090
“a's” frequency rank
#48,600
“AUC” frequency rank
63690
confusion score

Side-by-Side Comparison

Feature a's AUC
Definition plural of the letter a According to the Roman era, which reckons the number of years passed from the foundation of the city of Rome by Romulus, now usually taken as 753 bc.

Letter map: a's vs AUC

Shared letters muted; letters that set a's and AUC apart highlighted. Shared run: 1.

3 ch
a's
3 ch
AUC

Grammar separator: a's vs AUC

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: a's is anoun and AUCanadverb. On the page they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 63690, derived from the frequency rank of both members and their visual similarity.

a's is recorded at frequency rank #15,090, classified as anoun, pronounced /ˈeɪz/. AUC is at rank #48,600, tagged as anadv.

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 63690, this pair ranks #81,581 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of a's vs AUC

Shared letters: a. Private to "a's": s. Private to "AUC": cu.

"a's" · 2 letters · shape VC  ·  "AUC" · 3 letters · shape VVC

Frequently Asked Questions

Do "a's" and "AUC" mean the same thing in a sentence?
No - they are not even the same part of speech. "a's" is a noun and "AUC" an adverb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "a's" or "AUC"?
"a's" is the more common of the two: it sits at frequency rank #15,090 in our English list, against #48,600 for "AUC". 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 "a's" and "AUC".

  • Full dictionary entry for "a's" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "AUC" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #81,581 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "a's" and "AUC" also get mixed up with nearby pairs, the highest-scored neighbour is "amb vs AUC". Nearby pair

Confusion rank #81,581 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list