IvsioWhat's the difference?

Quick tell: I is a symbol, io is a noun, so they fill different roles in a sentence.

Which to use

“I” is a symbol and “io” is a noun - they look or sound alike but fill different roles in a sentence.

#381
“I” frequency rank
#23,588
“io” frequency rank
23969
confusion score

Side-by-Side Comparison

Feature I io
Definition Symbole chimique de l’iode. Septième lettre de l’alphabet cyrillique, ё.

Letter map: I vs io

Shared letters muted; letters that set I and io apart highlighted. Shared run: 1.

1 ch
I
2 ch
io

Part-of-speech tell for I / io

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: I is asymbol and ioanoun. On the page they differ by 1 extra letter(s) - “I” sits inside “io”. Our composite confusion score for this pair is 23969, derived from the frequency rank of both members and their visual similarity.

I is recorded at frequency rank #381, classified as asymbol. io is at rank #23,588, tagged as anoun, pronounced \jo\.

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 23969, this pair ranks #349,409 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of I vs io

Shared letters: i. Private to "I": -. Private to "io": o.

"I" · 1 letters · shape V  ·  "io" · 2 letters · shape VV

Frequently Asked Questions

Is swapping "I" for "io" ever safe?
No - they are not even the same part of speech. "I" is a symbol and "io" a noun, so a sentence built for one is usually ungrammatical with the other.
In ordinary French text, does "I" or "io" show up more?
"I" is the more common of the two: it sits at frequency rank #381 in our French list, against #23,588 for "io". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Done with this confusable. These links stay specific to "I" and "io".

  • Full dictionary entry for "I" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "io" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #349,409 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "I" and "io" also get mixed up with nearby pairs, the highest-scored neighbour is "io vs isi". Nearby pair

Confusion rank #349,409 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list