achvsarcoConfusable pair

Quick tell: ach is a intj, arco is a noun, so they fill different roles in a sentence.

Which to use

“ach” is an intj and “arco” is a noun - they look or sound alike but fill different roles in a sentence.

#48,212
“ach” frequency rank
#4,287
“arco” frequency rank
52499
confusion score

Side-by-Side Comparison

Feature ach arco
Definition oh ente geométrico cuja principal característica é a curva

Letter map: ach vs arco

Shared letters muted; letters that set ach and arco apart highlighted. Shared run: 2. ach runs 3 letters (VCC) against arco's 4 (VCCV) - the length gap alone is often enough to separate them once you know to check it.

3 ch
ach
4 ch
arco

Part-of-speech tell for ach / arco

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: ach is anintj and arcoanoun. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 52499, derived from the frequency rank of both members and their visual similarity.

ach is recorded at frequency rank #48,212, classified as anintj. arco is at rank #4,287, tagged as anoun, pronounced /ˈaɾ.ku/.

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 52499, this pair ranks #12,716 of 75,631 scored Portuguese confusable pairs - among the most confusable pairs.

Orthographic DNA of ach vs arco

Shared letters: ac. Private to "ach": h. Private to "arco": or.

"ach" · 3 letters · shape VCC  ·  "arco" · 4 letters · shape VCCV

Known mistypes of this pair

  • arco ← arcco · aroc · arrco · raco

Frequently Asked Questions

Is swapping "ach" for "arco" ever safe?
No - they are not even the same part of speech. "ach" is an intj and "arco" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "ach" or "arco"?
"arco" is the more common of the two: it sits at frequency rank #4,287 in our Portuguese list, against #48,212 for "ach". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

Pair "ach" vs "arco" is on the table, pick a follow-up below.

  • Full dictionary entry for "ach" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "arco" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #12,716 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "ach" and "arco" also get mixed up with nearby pairs, the highest-scored neighbour is "ach vs acs". 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 #12,716 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