CFF vs co, What's the Difference?

Which to use

“CFF” and “co” are a confusable French pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#46,639
“CFF” frequency rank: #1,856
“co” frequency rank: 48495
confusion score

Side-by-Side Comparison

Feature	CFF	co
Definition	Société anonyme (détenue à 100 % par la Confédération suisse) exploitant les chemins de fer suisses.	Connexion.

Where the eye mixes CFF and co

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

3 ch

CFF

2 ch

Look-alike desk: CFF vs co

A purely visual mix-up. CFF (\se.ɛf.ɛf\) and co (\ko\) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 48495, derived from the frequency rank of both members and their visual similarity.

CFF is recorded at frequency rank #46,639, classified as anoun, pronounced \se.ɛf.ɛf\. co is at rank #1,856, tagged as anoun, pronounced \ko\.

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 48495, this pair ranks #178,440 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of CFF vs co

Shared letters: c. Private to "CFF": f. Private to "co": o.

"CFF" · 3 letters · shape CCC · "co" · 2 letters · shape CV

Frequently Asked Questions

Is swapping "CFF" for "co" ever safe?

No. They are said differently (\se.ɛf.ɛf\ versus \ko\) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.

Which is more common, "CFF" or "co"?

"co" is the more common of the two: it sits at frequency rank #1,856 in our French list, against #46,639 for "CFF". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

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

Full dictionary entry for "CFF" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "co" - compare definitions side by side with the headword page. Word entry
This pair ranks #178,440 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
"CFF" and "co" also get mixed up with nearby pairs, the highest-scored neighbour is "CCE vs CFF". Nearby pair

Confusion rank #178,440 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.