iovsisoTell them apart

Which to use

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

#23,588
“io” frequency rank
#12,181
“iso” frequency rank
35769
confusion score

Side-by-Side Comparison

Feature io iso
Definition Septième lettre de l’alphabet cyrillique, ё. Plan isométrique.

Where the eye mixes io and iso

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

2 ch
io
3 ch
iso

Visual trap between io and iso

A purely visual mix-up. io (\jo\) and iso (\i.zo\) 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 35769, derived from the frequency rank of both members and their visual similarity.

io is recorded at frequency rank #23,588, classified as anoun, pronounced \jo\. iso is at rank #12,181, tagged as anoun, pronounced \i.zo\.

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 35769, this pair ranks #274,370 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of io vs iso

Shared letters: io. Private to "io": -. Private to "iso": s.

"io" · 2 letters · shape VV  ·  "iso" · 3 letters · shape VCV

Frequently Asked Questions

Can "io" and "iso" be used interchangeably?
No. They are said differently (\jo\ versus \i.zo\) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Which is more common, "io" or "iso"?
"iso" is the more common of the two: it sits at frequency rank #12,181 in our French list, against #23,588 for "io". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

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

  • Full dictionary entry for "io" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "iso" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #274,370 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "io" and "iso" also get mixed up with nearby pairs, the highest-scored neighbour is "io vs isi". Nearby pair

Confusion rank #274,370 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