bug vs but, What's the Difference?

Which to use

“bug” is a noun and “but” is a preposition - they look or sound alike but fill different roles in a sentence.

#5,105
“bug” frequency rank: #25
“but” frequency rank: 5130
confusion score

Side-by-Side Comparison

Feature	bug	but
Definition	An insect of the order Hemiptera (the “true bugs”).	Apart from, except (for), excluding.

Where the eye mixes bug and but

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

3 ch

bug

3 ch

but

Look-alike desk: bug vs but

These two trip readers on the page rather than in the ear: bug is /bʌɡ/ while but is /ˈbʌt/. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - g in “bug” becomes t in “but”, and the parts of speech differ too (noun vs preposition), which is usually the fastest check. Our composite confusion score for this pair is 5130, derived from the frequency rank of both members and their visual similarity.

bug is recorded at frequency rank #5,105, classified as anoun, pronounced /bʌɡ/. but is at rank #25, tagged as aprep, pronounced /ˈbʌt/.

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 5130, this pair ranks #516,472 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of bug vs but

Shared letters: bu. Private to "bug": g. Private to "but": t.

"bug" · 3 letters · shape CVC · "but" · 3 letters · shape CVC

Frequently Asked Questions

Do "bug" and "but" mean the same thing in a sentence?

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

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

"but" is the more common of the two: it sits at frequency rank #25 in our English list, against #5,105 for "bug". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

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 "bug" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "but" - compare definitions side by side with the headword page. Word entry
This pair ranks #516,472 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"bug" and "but" also get mixed up with nearby pairs, the highest-scored neighbour is "BFS vs bug". Nearby pair

Confusion rank #516,472 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.