but vs by, What's the Difference?

Which to use

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

#11,178
“but” frequency rank: #2,381
“by” frequency rank: 13559
confusion score

Side-by-Side Comparison

Feature	but	by
Definition	Muy.	A, en.

Where the eye mixes but and by

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

3 ch

but

2 ch

Look-alike desk: but vs by

These two trip readers on the page rather than in the ear: but is [ˈbut̪] 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 (adverb vs preposition), which is usually the fastest check. Our composite confusion score for this pair is 13559, derived from the frequency rank of both members and their visual similarity.

but is recorded at frequency rank #11,178, classified as anadv, pronounced [ˈbut̪]. 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 13559, this pair ranks #287,407 of 323,831 scored Spanish confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of but vs by

Shared letters: b. Private to "but": tu. Private to "by": y.

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

Frequently Asked Questions

Is swapping "but" for "by" ever safe?

No - they are not even the same part of speech. "but" is an adverb and "by" a preposition, so a sentence built for one is usually ungrammatical with the other.

Which is more common, "but" or "by"?

"by" is the more common of the two: it sits at frequency rank #2,381 in our Spanish list, against #11,178 for "but". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

Full dictionary entry for "but" 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 #287,407 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
"but" and "by" also get mixed up with nearby pairs, the highest-scored neighbour is "but vs butt". Nearby pair

Confusion rank #287,407 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.