birvsbyWhat's the difference?

Quick tell: bir is a num, by is a preposition, so they fill different roles in a sentence.

Which to use

“bir” is a num and “by” is a preposition - they look or sound alike but fill different roles in a sentence.

#48,247
“bir” frequency rank
#2,381
“by” frequency rank
50628
confusion score

Side-by-Side Comparison

Feature bir by
Definition Uno, un. A, en.

Where the eye mixes bir and by

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch
bir
2 ch
by

Look-alike desk: bir vs by

These two trip readers on the page rather than in the ear: bir is [bir] while by is [bɛi]. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (num vs preposition), which is usually the fastest check. Our composite confusion score for this pair is 50628, derived from the frequency rank of both members and their visual similarity.

bir is recorded at frequency rank #48,247, classified as anum, pronounced [bir]. by is at rank #2,381, tagged as aprep, pronounced [bɛi].

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 50628, this pair ranks #102,179 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of bir vs by

Shared letters: b. Private to "bir": ir. Private to "by": y.

"bir" · 3 letters · shape CVC  ·  "by" · 2 letters · shape CV

Frequently Asked Questions

Can "bir" and "by" be used interchangeably?
No - they are not even the same part of speech. "bir" is a num and "by" a preposition, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "bir" vs "by" - which ranks higher?
"by" is the more common of the two: it sits at frequency rank #2,381 in our Spanish list, against #48,247 for "bir". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

Eye-level mix-up between "bir" and "by" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "bir" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "by" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #102,179 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "bir" and "by" also get mixed up with nearby pairs, the highest-scored neighbour is "bir vs brie". Nearby pair

Confusion rank #102,179 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list