Which to use
“ii” is an adverb and “ion” is a noun - they look or sound alike but fill different roles in a sentence.
- #627
- “ii” frequency rank
- #14,064
- “ion” frequency rank
- 14691
- confusion score
Side-by-Side Comparison
| Feature | ii | ion |
|---|---|---|
| Definition | Oui. | Atome ou molécule ayant perdu ou gagné des électrons sur sa couche externe. |
Where the eye mixes ii and ion
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Why the eye confuses ii with ion
These two trip readers on the page rather than in the ear: ii is \iː\ while ion is \jɔ̃\. 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 (adverb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 14691, derived from the frequency rank of both members and their visual similarity.
ii is recorded at frequency rank #627, classified as anadv, pronounced \iː\. ion is at rank #14,064, tagged as anoun, pronounced \jɔ̃\.
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 14691, this pair ranks #395,596 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of ii vs ion
Shared letters: i. Private to "ii": -. Private to "ion": no.
"ii" · 2 letters · shape VV · "ion" · 3 letters · shape VVC
Frequently Asked Questions
Can "ii" and "ion" be used interchangeably?
Frequency check: "ii" vs "ion" - which ranks higher?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "ii" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "ion" - compare definitions side by side with the headword page. Word entry
- This pair ranks #395,596 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "ii" and "ion" also get mixed up with nearby pairs, the highest-scored neighbour is "ion vs isi". Nearby pair
Confusion rank #395,596 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.