is vs ith, What's the Difference?

Which to use

“is” is a verb and “ith” is an adjective - they look or sound alike but fill different roles in a sentence.

#8
“is” frequency rank: #49,435
“ith” frequency rank: 49443
confusion score

Side-by-Side Comparison

Feature	is	ith
Definition	third-person singular simple present indicative of be	Occurring at position i in a sequence.

Where the eye mixes is and ith

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

2 ch

3 ch

ith

Visual trap between is and ith

These two trip readers on the page rather than in the ear: is is /ɪz/ while ith is /aɪθ/. 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 (verb vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 49443, derived from the frequency rank of both members and their visual similarity.

is is recorded at frequency rank #8, classified as averb, pronounced /ɪz/. ith is at rank #49,435, tagged as anadj, pronounced /aɪθ/.

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 49443, this pair ranks #183,553 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of is vs ith

Shared letters: i. Private to "is": s. Private to "ith": ht.

"is" · 2 letters · shape VC · "ith" · 3 letters · shape VCC

Frequently Asked Questions

Can "is" and "ith" be used interchangeably?

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

In ordinary English text, does "is" or "ith" show up more?

"is" is the more common of the two: it sits at frequency rank #8 in our English list, against #49,435 for "ith". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

Full dictionary entry for "is" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "ith" - compare definitions side by side with the headword page. Word entry
This pair ranks #183,553 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"is" and "ith" also get mixed up with nearby pairs, the highest-scored neighbour is "ISR vs ith". Nearby pair

Confusion rank #183,553 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.