K vs key, What's the Difference?

Which to use

“K” is a character and “key” is an adjective - they look or sound alike but fill different roles in a sentence.

#1,616
“K” frequency rank: #10,384
“key” frequency rank: 12000
confusion score

Side-by-Side Comparison

Feature	K	key
Definition	a décima primeira letra do alfabeto português, precedida por J e seguida por L	indispensável

Where the eye mixes K and key

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

1 ch

3 ch

key

Look-alike desk: K vs key

These two trip readers on the page rather than in the ear: K is /ka/ while key is /kiː/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “K” sits inside “key”, and the parts of speech differ too (character vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 12000, derived from the frequency rank of both members and their visual similarity.

K is recorded at frequency rank #1,616, classified as acharacter, pronounced /ka/. key is at rank #10,384, tagged as anadj, pronounced /kiː/.

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 12000, this pair ranks #60,712 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of K vs key

Shared letters: k. Private to "K": -. Private to "key": ey.

"K" · 1 letters · shape C · "key" · 3 letters · shape CVV

Frequently Asked Questions

Do "K" and "key" mean the same thing in a sentence?

No - they are not even the same part of speech. "K" is a character and "key" an adjective, so a sentence built for one is usually ungrammatical with the other.

In ordinary Portuguese text, does "K" or "key" show up more?

"K" is the more common of the two: it sits at frequency rank #1,616 in our Portuguese list, against #10,384 for "key". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

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

Full dictionary entry for "K" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "key" - compare definitions side by side with the headword page. Word entry
This pair ranks #60,712 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"K" and "key" also get mixed up with nearby pairs, the highest-scored neighbour is "K7 vs key". Nearby pair

Confusion rank #60,712 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.