com vs cu, What's the Difference?

Which to use

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

#14
“com” frequency rank: #4,716
“cu” frequency rank: 4730
confusion score

Side-by-Side Comparison

Feature	com	cu
Definition	indica várias relações: companhia, causa, instrumento, ligação, modo, oposição	extremidade do intestino grosso; ânus

Where the eye mixes com and cu

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

3 ch

com

2 ch

Look-alike desk: com vs cu

These two trip readers on the page rather than in the ear: com is /kõ/ while cu is /ˈku/. 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 (preposition vs noun), which is usually the fastest check. Our composite confusion score for this pair is 4730, derived from the frequency rank of both members and their visual similarity.

com is recorded at frequency rank #14, classified as aprep, pronounced /kõ/. cu is at rank #4,716, tagged as anoun, pronounced /ˈku/.

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 4730, this pair ranks #70,072 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of com vs cu

Shared letters: c. Private to "com": mo. Private to "cu": u.

"com" · 3 letters · shape CVC · "cu" · 2 letters · shape CV

Frequently Asked Questions

Can "com" and "cu" be used interchangeably?

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

Frequency check: "com" vs "cu" - which ranks higher?

"com" is the more common of the two: it sits at frequency rank #14 in our Portuguese list, against #4,716 for "cu". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

Full dictionary entry for "com" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "cu" - compare definitions side by side with the headword page. Word entry
This pair ranks #70,072 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"com" and "cu" also get mixed up with nearby pairs, the highest-scored neighbour is "chau vs cu". Nearby pair

Confusion rank #70,072 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.