Which to use
“ion” is a noun and “iu” is a pronoun - they look or sound alike but fill different roles in a sentence.
- #14,064
- “ion” frequency rank
- #46,833
- “iu” frequency rank
- 60897
- confusion score
Side-by-Side Comparison
| Feature | ion | iu |
|---|---|---|
| Definition | Atome ou molécule ayant perdu ou gagné des électrons sur sa couche externe. | Je. |
Where the eye mixes ion and iu
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence. ion runs 3 letters (VVC) against iu's 2 (VV) - the length gap alone is often enough to separate them once you know to check it.
Why the eye confuses ion with iu
These two trip readers on the page rather than in the ear: ion is \jɔ̃\ while iu is \ˈiu\. 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 (noun vs pronoun), which is usually the fastest check. Our composite confusion score for this pair is 60897, derived from the frequency rank of both members and their visual similarity.
ion is recorded at frequency rank #14,064, classified as anoun, pronounced \jɔ̃\. iu is at rank #46,833, tagged as apron, pronounced \ˈiu\.
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 60897, this pair ranks #95,215 of 440,172 scored French confusable pairs - among the most confusable pairs.
Orthographic DNA of ion vs iu
Shared letters: i. Private to "ion": no. Private to "iu": u.
"ion" · 3 letters · shape VVC · "iu" · 2 letters · shape VV
Frequently Asked Questions
Can "ion" and "iu" be used interchangeably?
Which is more common, "ion" or "iu"?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "ion" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "iu" - compare definitions side by side with the headword page. Word entry
- This pair ranks #95,215 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "ion" and "iu" also get mixed up with nearby pairs, the highest-scored neighbour is "isi vs iu". Nearby pair
Confusion rank #95,215 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.