invsISBNWhich spelling fits?

Quick tell: in is a preposition, ISBN is an abbrev, so they fill different roles in a sentence.

Which to use

“in” is a preposition and “ISBN” is an abbrev - they look or sound alike but fill different roles in a sentence.

#269
“in” frequency rank
#11,899
“ISBN” frequency rank
12168
confusion score

Side-by-Side Comparison

Feature in ISBN
Definition em sigla formada com as iniciais de International Standard Book Number, sequência numérica de dez ou treze dígitos com a finalidade de identificação numérica de um livro segundo seu título, autor, país, ou código de idioma, e a editora, individualizando inclusive edições diferentes de tal forma que cada livro tenha um número próprio e único

Letter map: in vs ISBN

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

2 ch
in
4 ch
ISBN

Grammar separator: in vs ISBN

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: in is apreposition and ISBNanabbrev. On the page they differ by 2 letter(s) in length. Our composite confusion score for this pair is 12168, derived from the frequency rank of both members and their visual similarity.

in is recorded at frequency rank #269, classified as aprep. ISBN is at rank #11,899, tagged as anabbrev.

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 12168, this pair ranks #60,507 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of in vs ISBN

Shared letters: in. Private to "in": -. Private to "ISBN": bs.

"in" · 2 letters · shape VC  ·  "ISBN" · 4 letters · shape VCCC

Known mistypes of this pair

  • ISBN ← ibsn · isbbn · isbnn · isnb · issbn · sibn

Frequently Asked Questions

Can "in" and "ISBN" be used interchangeably?
No - they are not even the same part of speech. "in" is a preposition and "ISBN" an abbrev, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "in" vs "ISBN" - which ranks higher?
"in" is the more common of the two: it sits at frequency rank #269 in our Portuguese list, against #11,899 for "ISBN". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

Pair "in" vs "ISBN" is on the table, pick a follow-up below.

  • Full dictionary entry for "in" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "ISBN" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #60,507 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "in" and "ISBN" also get mixed up with nearby pairs, the highest-scored neighbour is "íon vs ISBN". 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 #60,507 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