archvsarmWhich spelling fits?

Quick tell: arch is a verb, arm is an adjective, so they fill different roles in a sentence.

Which to use

“arch” is a verb and “arm” is an adjective - they look or sound alike but fill different roles in a sentence.

#35,879
“arch” frequency rank
#27,355
“arm” frequency rank
63234
confusion score

Side-by-Side Comparison

Feature arch arm
Definition arquear, tomar a forma de um arco pobre

Letter map: arch vs arm

Shared letters muted; letters that set arch and arm apart highlighted. Shared run: 2.

4 ch
arch
3 ch
arm

Part-of-speech tell for arch / arm

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: arch is averb and armanadjective. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 63234, derived from the frequency rank of both members and their visual similarity.

arch is recorded at frequency rank #35,879, classified as averb. arm is at rank #27,355, tagged as anadj, pronounced /aʁm/ ouvir^(fonte ?).

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 63234, this pair ranks #6,284 of 75,631 scored Portuguese confusable pairs - among the most confusable pairs.

Orthographic DNA of arch vs arm

Shared letters: ar. Private to "arch": ch. Private to "arm": m.

"arch" · 4 letters · shape VCCC  ·  "arm" · 3 letters · shape VCC

Known mistypes of this pair

  • archacrh · arcch · archh · arhc · arrch · rach

Frequently Asked Questions

Is swapping "arch" for "arm" ever safe?
No - they are not even the same part of speech. "arch" is a verb and "arm" an adjective, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "arch" vs "arm" - which ranks higher?
"arm" is the more common of the two: it sits at frequency rank #27,355 in our Portuguese list, against #35,879 for "arch". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Done with this confusable. These links stay specific to "arch" and "arm".

  • Full dictionary entry for "arch" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "arm" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #6,284 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "arch" and "arm" also get mixed up with nearby pairs, the highest-scored neighbour is "acs vs arch". 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 #6,284 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list