Which to use
“an” is an article and “arm” is a noun - they look or sound alike but fill different roles in a sentence.
- #30
- “an” frequency rank
- #1,887
- “arm” frequency rank
- 1917
- confusion score
Side-by-Side Comparison
| Feature | an | arm |
|---|---|---|
| Definition | Form of a (all article senses). | The portion of the upper human appendage, from the shoulder to the wrist and sometimes including the hand. |
Where the spellings diverge
Shared letters are muted; the letters that actually set an and arm apart are highlighted. They share 1 letter in sequence, which is exactly why the eye skips the difference.
Spelling & Dictionary Insight
an and arm form a confusable pair in the English index, two distinct headwords that are easily confused because they look alike, sound alike, or both. They differ by 1 letter(s) in length - close enough that the eye skips over the difference, far enough that meaning fully diverges. Our composite confusion score for this pair is 1917, derived from the frequency rank of both members and their visual similarity.
an is recorded at frequency rank #30, classified as anarticle, pronounced /ˈæn/. arm is at rank #1,887, tagged as anoun, pronounced /ɑːm/.
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 1917, this pair ranks #526,305 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Frequency comparison
Frequently Asked Questions
Can "an" and "arm" be used interchangeably?
Remembering an vs arm
The fastest way to pick the right one every time.
- Check the role first: if you need an article, it's “an”; for a noun, it's “arm”.
- See each word in full, definition, IPA, etymology and its other confusables. Full “an” entry
- Browse more pairs most likely to be confused. Most confusable