Which to use
“io” is a noun and “iz” is a verb - they look or sound alike but fill different roles in a sentence.
- #16,946
- “io” frequency rank
- #32,457
- “iz” frequency rank
- 49403
- confusion score
Side-by-Side Comparison
| Feature | io | iz |
|---|---|---|
| Definition | A type of moth, the io moth. | third-person singular simple present indicative of be |
Letter map: io vs iz
Shared letters muted; letters that set io and iz apart highlighted. Shared run: 1.
Grammar separator: io vs iz
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: io is anoun and izaverb. On the page they differ by a single letter - o in “io” becomes z in “iz”. Our composite confusion score for this pair is 49403, derived from the frequency rank of both members and their visual similarity.
io is recorded at frequency rank #16,946, classified as anoun, pronounced /ˈaɪəʊ/. iz is at rank #32,457, tagged as averb.
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 49403, this pair ranks #183,945 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of io vs iz
Shared letters: i. Private to "io": o. Private to "iz": z.
"io" · 2 letters · shape VV · "iz" · 2 letters · shape VC
Frequently Asked Questions
Is swapping "io" for "iz" ever safe?
Which is more common, "io" or "iz"?
After this comparison
Pair "io" vs "iz" is on the table, pick a follow-up below.
- Full dictionary entry for "io" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "iz" - compare definitions side by side with the headword page. Word entry
- This pair ranks #183,945 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "io" and "iz" also get mixed up with nearby pairs, the highest-scored neighbour is "ith vs iz". Nearby pair
Confusion rank #183,945 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.