is vs iso, What's the Difference?

Which to use

“is” is a verb and “iso” is a noun - they look or sound alike but fill different roles in a sentence.

#8
“is” frequency rank: #9,771
“iso” frequency rank: 9779
confusion score

Side-by-Side Comparison

Feature	is	iso
Definition	third-person singular simple present indicative of be	Clipping of isolation.

Where the eye mixes is and iso

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

2 ch

3 ch

iso

Why the eye confuses is with iso

These two trip readers on the page rather than in the ear: is is /ɪz/ while iso is /ˈaɪsəʊ/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 extra letter(s) - “is” sits inside “iso”, and the parts of speech differ too (verb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 9779, derived from the frequency rank of both members and their visual similarity.

is is recorded at frequency rank #8, classified as averb, pronounced /ɪz/. iso is at rank #9,771, tagged as anoun, pronounced /ˈaɪsəʊ/.

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 9779, this pair ranks #495,641 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of is vs iso

Shared letters: is. Private to "is": -. Private to "iso": o.

"is" · 2 letters · shape VC · "iso" · 3 letters · shape VCV

Frequently Asked Questions

Is swapping "is" for "iso" ever safe?

No - they are not even the same part of speech. "is" is a verb and "iso" a noun, so a sentence built for one is usually ungrammatical with the other.

Which is more common, "is" or "iso"?

"is" is the more common of the two: it sits at frequency rank #8 in our English list, against #9,771 for "iso". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

Eye-level mix-up between "is" and "iso" is sorted above. Next: full entries or other pairs that share a letter shape.

Full dictionary entry for "is" 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 #495,641 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"is" and "iso" also get mixed up with nearby pairs, the highest-scored neighbour is "iso vs ith". Nearby pair

Confusion rank #495,641 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.