ion vs is, What's the Difference?

Which to use

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

#5,604
“ion” frequency rank: #8
“is” frequency rank: 5612
confusion score

Side-by-Side Comparison

Feature	ion	is
Definition	An atom or group of atoms bearing an electrical charge, such as the sodium and chlorine atoms in a salt solution.	third-person singular simple present indicative of be

Where the eye mixes ion and is

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch

ion

2 ch

Why the eye confuses ion with is

These two trip readers on the page rather than in the ear: ion is /ˈaɪən/ while is is /ɪz/. 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 verb), which is usually the fastest check. Our composite confusion score for this pair is 5612, derived from the frequency rank of both members and their visual similarity.

ion is recorded at frequency rank #5,604, classified as anoun, pronounced /ˈaɪən/. is is at rank #8, tagged as averb, pronounced /ɪz/.

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 5612, this pair ranks #514,644 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of ion vs is

Shared letters: i. Private to "ion": no. Private to "is": s.

"ion" · 3 letters · shape VVC · "is" · 2 letters · shape VC

Frequently Asked Questions

Do "ion" and "is" mean the same thing in a sentence?

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

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

"is" is the more common of the two: it sits at frequency rank #8 in our English list, against #5,604 for "ion". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

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

Full dictionary entry for "ion" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "is" - compare definitions side by side with the headword page. Word entry
This pair ranks #514,644 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"ion" and "is" also get mixed up with nearby pairs, the highest-scored neighbour is "Ilan vs ion". Nearby pair

Confusion rank #514,644 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.