Which to use
“ai” is a noun and “an” is an article - they look or sound alike but fill different roles in a sentence.
- #4,818
- “ai” frequency rank
- #30
- “an” frequency rank
- 4848
- confusion score
Side-by-Side Comparison
| Feature | ai | an |
|---|---|---|
| Definition | A type of three-toed sloth, Bradypus tridactylus, endemic to forests of southern Venezuela, the Guianas, and northern Brazil. | Form of a (all article senses). |
Where the eye mixes ai and an
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Why the eye confuses ai with an
These two trip readers on the page rather than in the ear: ai is /ˈɑ.i/ while an is /ˈæn/. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - i in “ai” becomes n in “an”, and the parts of speech differ too (noun vs article), which is usually the fastest check. Our composite confusion score for this pair is 4848, derived from the frequency rank of both members and their visual similarity.
ai is recorded at frequency rank #4,818, classified as anoun, pronounced /ˈɑ.i/. an is at rank #30, tagged as anarticle, pronounced /ˈæn/.
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 4848, this pair ranks #517,460 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of ai vs an
Shared letters: a. Private to "ai": i. Private to "an": n.
"ai" · 2 letters · shape VV · "an" · 2 letters · shape VC
Frequently Asked Questions
Is swapping "ai" for "an" ever safe?
In ordinary English text, does "ai" or "an" show up more?
After this comparison
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "ai" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "an" - compare definitions side by side with the headword page. Word entry
- This pair ranks #517,460 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "ai" and "an" also get mixed up with nearby pairs, the highest-scored neighbour is "ai vs amb". Nearby pair
Confusion rank #517,460 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.